Reduce your frustration?? YES, unless it does not bother you that small errors crept up and make things not quite square, drawers sticks, if they open, and trying to juggle an enormous amount of clamps in the vain hope of closing some recalcitrant joints, then NO, you don't need any I guess....
Before any wood is to be cut you need some layout lines.
Lines to guide the following operations, cutting to it.
Because it leave a line of a certain thickness, which is really not straight but slightly tapering as the lead is wearing, it cannot be precise. No matter what.
Having said that, they still have their place and a white colored pencil is handy on dark colored woods like walnuts. Reserved these for initial rough cuts.
They come in a surprising varieties, often based on ethnic origins. The English, the German, the French, the Japanese knife and etc.
The marking knife leaves a crisp incised line which your saw or chisel can easily follow, bang on. There is no guessing which sides of the line to cut, split the line etc. The line is THE line.
In order to do that, it needs to be sharpened with a single bevel. This will result in a cut with a straight wall up down follow by a tapering width.
That crisp line on top of your piece will become your finish cut on top. A nice sharply defined line, not a ragged line with saw fuzz or butchered with errand tool cuts.
Often running a pencil lead over the cut line will make it more stand out. Oftentimes, the resulting line may be wavering, but it does not matter, your tools will still seek and rest in the "line".
They comes in a variety of styles and shapes, but to be considered a true marking knife, it must be sharpen on one side only. One bevel, not two like on most knifes. They comes in pairs, left and right hand versions or with both sides by using a spear point. Strictly a matter of preferences, depending how you work. Myself, I prefer my Czeck knife because of its thin long blade, it is great for markings dovetails parts. But unless you cut dovetails by hands, you may never need its thinness.
Marking gauges
Wood or metal, shop made or purchased, get at least one.
They leave a mark by either scratching, cutting or slicing.
Depending if riding across the grain (width of board) or alongside, the type of cutter makes a small difference. Properly sharpened and set up, they should leave a mark in the same V shape cut line as the marking knife. One wall straight, the other tapering out on the waste side. The resulting lines act as guides for the next tools.
A good compromise between the various types, is the circular cutter one. Leave a crisp line across grain and does not as easily veered off and follow the grain direction while running along the grain.
Very easy to sharpen but you can replace the cutter easily also
They also make micro adjustable version. The gold standard being the Tite-Mark gauges.
Veritas makes a micro-adjust version also
What do you do when your marking gauge is smaller than the board you want to scribe? That is when you used a Panel gauge. Used mostly to scribe a board for ripping to width.
You may have noticed, I mentioned "Reference Edge". Both the Try square and marking gauges rely on either a straight flat face (reference face) or a flat and square to the face, reference edge.
Hint both reference face and edge are done on the 6 in or 8 in jointer. The very first operations to be done to your board (except to cross cut it in more manageable pieces) before sending them thru the planer then the table saw. You then end up with flatish, squarish boards of evenish width. Huh ???
All of these defects can be minimized by using the proper types of blades for the operation, watching your feed rates, making boards a bit bigger than final dimensions for a quick clean up after.
All these defects are going to throw out the window any accuracy in your measurements, layout, caused problems at assembly etc. Fortunately, easily rectified
Face, Edge, Width, Thickness, End, Length
F - A few swipes of your No 5 Jack with its square edge blade, maybe some touch ups with a card scraper and you have a very flat and out of twist board (check with winding sticks). Mark it as your reference face
E- A few swipes of your No 5 Jack turned, jointer and your edge is flat and square to your face (check with Try Square) Mark it as your reference edge.
From now on ALWAYS reference to this edge with your tools
The W-idth and T-hickness is already close enough, off the power tools.
E-L- Next we need a square end to be able to measure our final length.
A few pass on your shooting board will give you glass smooth ends without spelching. Check with Try Square.
The point is before any layout or measurements are attempted on your board, you need to have established FIRST a reference face and edge.
Squares.
Surprisingly, not all squares are made totally square or remain so down the road. Fortunately for us, it is easy to check a square for being square.
Even if you already checked it previously and found it square, it is a good idea to check them often to avoid frustrations down the road... Just saying.
For the above reasons, stay away from the nice looking wood handles ones and simply buy inexpensive Machinist grade B squares. Groz often on sale at Busy Bee are a good source of inexpensive precision squares. While you can pay up to $366 USD for a machinist 6 in square, we are woodworkers not machinist. Grade B is plenty good for us and much more affordable.
You don't need the whole set, of which sizes there are many more than shown, but a 6 in and a smaller 3-4 incher are very handy.
Combination square
This is where you are going to spend all the money I saved you so far. You want and need all the precision you can afford in this very versatile tool. So versatile you would be reaching often for it. It is a depth gauge, a straight edge, a ruler, a 90 or 45 degrees square a center finder, a level etc.
Stay away from the hardware stores variety and buy a real good one such as Starrett or other renown machinist tools maker.
Guess who first came out with this form? Starrett and they still know how to make them to last.
Which is exactly what is wrong with most other El Cheapo squares. They either don't lock square to start with or they loose that ability down the road to wear and tear. I had one which broke the pawl that lock the blade rendering it useless.
You don't want a head in plastic or Zamak, Aluminum etc. You want good old cast iron with precision machined surfaces. Not moulded, not milled... machined! That is what you are paying the big $$ for, accuracy. Don't skimp on it, take good care of it and it will serve you and your untold future generations for years and years. Get the 12 inch. Worth the money.
They make a center finding head and a angle reporting head for it, sold separately or as part of the whole set. Save your money, you don't need these.
You can also buy different sizes rulers or with various markings, including ..yuck.. Metric :-)
Of course, not everything is square...
For these times you need a simple Sliding T bevel square
They come in a variety of styles, but they mostly all have the same fault... except those that lock on the butt end.
If looking for vintage, looks for Stanley No 18 T bevel square and clones
Thankfully you can buy new ones for a decent prices at Lee Valley, that meet the criteria's required...
The pinch rods or sticks.
You probably been told that to ensure squareness at glue times we measure the diagonals corners and they should be the same, if not we are not square. Very true, but the frustration quickly comes trying to fit the tape and measure the same on both diagonals while juggling an armful pile of clamps. At best some imprecise approximation.
An easier way is using a pair of pinch sticks with tapering ends. You simply slide it inside box, set the rods to fit corners to corners, lock rods and try other diagonal, if square will fit exactly. Cannot get anymore precise and no math's involved figuring out the differences.
Easy to makes, make a few sizes, to fit whatever sizes you often work with. Remember they are adjustable. I used this hardware kit from LV to make mine, but you can use whatever you can think of.
Watch Pinch rods and squeezy blocks with Roy Underhill make one with pieces of plumbing pipes coupler in Season 2014-15
A pair of winding sticks. Another Easy Peasy project. You can make them as fancy as you want or just go to the hardware store, pick up a length of angle iron or aluminum. Cut in half, make some markings with a sharpie and voila. They will stay put better (stable) on your board, resting on the open legs of the angle and you will not cry such as when your fancy $189.99 USD wooden winding sticks fall off the board or the bench and bounce off the cement floor... And yes, your El Cheapo will works just as fine. Even after dropping it a few times :-)
They are used to detect winding or twist in boards. If you put in a winding board inside the planer, you will get a flat but still in wind board. Banana in, banana out. You need a flat side first. Normally done on the jointer or with our jack plane turned scrub plane. Also handy to detect twist in assemblies, introduced by unsquared boards, gaps in joinery, clamps pressures etc.
Make or buy one, it truly is essential.
Compass and Dividers
Just what you need to scribe small arc or stepping up distances equally.
A 6 or 8 in divider should handle anything your way.. They of course comes in smaller (4 in) and larger (10, 12 in).
Trammels points, pair of
How do you scribe radius bigger than your biggest compass? Trammels points.
They are used with a stick of whatever suitable length, and allows you to swing an arc of whatever radius. Much, much easier than trying to use a very large compass.
Go No Go gauges
Another easy way to avoid measurements errors is to use a "Standard" such as set up blocks.
Set up blocks make setting up your machines that much easier and precise. And non surprisingly, make setting up our hand planes easier too :-)
Veritas set up blocks shown above. I have the whole set with add ons, I love these.
The depth gauge shown is an earlier version of their current tool
There are so much more gauges and tools I could show you, but I am trying very hard to keep it simple and essential.
We could debate "essential" for ever, but in this case it is meant to show you some simple basic tools that will really enhance your woodworking. By working easier, safer (?? does band aids count??:-) and more precise.
So there you have it, your complete essential minimalist tool kit
Cost?? Depends a lot if you buy all new or scour the flea markets/yard sales or online auctions like Kijiji etc. Knowing what to look for is half the battle. The other half is finding it :-)
Always buy the best tools you can afford in what ever budget, you will never regret it, and they will last you centuries.
Comments welcomes
Bob, bursting with tools to add... :-)