In the sixty years of woodworking I have found two tools of increasing necessity. One is a band saw. I can do most of my work with a band saw and hand plane. The second tool is a bow saw, or actually several bow saws. They will replace the band saw if required, though they are slow. One I made about twenty years ago has a one and a half inch wide rip blade and is about thirty inches long. I think the blade is from an old industrial band saw blade I picked up and sharpened into a rip saw blade. It works very well on ripping lumber, logs, etc. Though it tires me out to much to use it now.
A layout square, or combination square, comes in 6” and 12” sizes. Most woodworkers use the 6” model, simply because it’s easiest to carry around. Also, most of the stock you’ll use will be no bigger than 6” wide, so 12” is overkill. The layout square is a triangle that you can use to mark square cuts on stock. Once you measure the length of the cut, you line up the layout square with the edge of the board. The short side will give you a straight, square cut across the end grain. You can also measure off angles with the layout square. This helps when you’re trying to measure for a bevel on a table saw, or marking a cut for a miter saw. You can even use your layout square to determine an existing angle. Just be sure to buy one made of metal. The plastic ones are not only fragile, but they also can warp, making them pretty useless.