Cutting all your shelf pieces to size
Okay. So this is the lesson where it all comes together. You've got your reference edge, you've got your marking down, you've got the hand saw and the table saw both under your belt, and now we're going to cut every piece your shelf needs, in one sitting, so you've got a full set of parts in front of you instead of a pile of half-finished ideas.
I feel like this is the point in a project where people either get organized or get sloppy, and there's not much middle ground. So let's get organized.
Start with a cut list, on paper
Before you touch a saw today, write down every piece your shelf needs. For the basic shelf we've been building, that's usually two sides, a bottom, a top, and however many shelf boards you decided on back when we talked about the design. Write the length of each one next to it.
Then do something I think people skip because it feels like an extra step. Mark which pieces are actually identical. Your two sides should be the exact same length. If you cut them separately, measuring fresh each time, you're giving yourself two chances to be a little bit off, and then your shelf sits crooked and you spend the rest of the build compensating for it. Instead, cut one side, check it against your square, and then use that piece as your actual measuring reference for the second one. Line them up edge to edge and mark straight across. That way if there's an error, both pieces have the same error, and it's a lot less noticeable than two different errors fighting each other.
Order matters more than people think
Cut your longest pieces first. This sounds like a small thing but it isn't. If you cut a short piece first and then realize you're one board short for the long side, you've wasted material. Longest to shortest, every time, and you'll get the most out of the lumber you bought.
Check the board before you touch it with a blade
Before every single cut, and I mean every one, run your hand down the board and look at it. Look for knots, look for anything that doesn't look like clean wood, and if you're working with a board that's been sitting around your garage a while, or came from somewhere other than a fresh trip to buy lumber, look for hardware. Nails, screws, staples, anything metal that got left in there from a board's previous life.
I've got a saw blade hanging on my wall in the shop right now with a nick in it, and it's there because I didn't do this once. I was cutting into a board I'd had sitting around, moving fast because I was excited to get to the next step, and I ran the blade straight into a screw I never checked for. Blade's ruined. Board's ruined. And it startled me pretty good, because it's not a small sound, metal on metal at that speed. I kept the blade. It's not a trophy, it's just a reminder to slow down for about five seconds and actually look at what I'm about to cut. Costs you nothing. Saves you a blade, or worse, a hand.
Cutting the pieces
For the sides and the top and bottom, you can use either the hand saw or the table saw at this point, whichever you're more comfortable with, but if you're using the table saw, set your fence once per length and cut all the matching pieces before you move the fence again. Don't reset the fence, cut one piece, reset it again for what you think is the same length, cut another. That's how small differences creep in. Set it once, cut everything that length, then move on.
For the shelf boards themselves, same rule. If you need three shelves the same width, set up once and cut all three back to back.
After each cut, check it against your square, same as we practiced. Don't wait until the end to check everything at once. If something's off, you want to know now, while you can still adjust, not after you've cut four more pieces to match a mistake.
Label as you go
This feels like a small thing and it isn't. Take a pencil and write directly on each piece what it is. "Left side." "Shelf 1." "Top." It feels a little silly when the pieces are laid out in front of you and it's obvious, but once you've got glue and clamps involved a few lessons from now, obvious stops being obvious, especially if two pieces are close in size. I've mixed up which side was which before. It's a small annoyance when it happens and it's a five-second habit to prevent it.
A word on softwood here
If you went with pine for this project, which I'd recommend for a first build, you'll notice it cuts easy and forgiving. That's the whole point of starting with something cheap and soft. If a cut goes a little rough or you tear out a bit of grain on an edge, it's not a disaster and it's not expensive to fix or replace. Save the hardwood for after you trust your hands a little more.
Before next time
Lay all your cut pieces out on your workbench in the shape of the finished shelf, even without any glue or screws, and just look at it for a minute. Next lesson we start putting it together for real.