The Square Knot, Slow, Twice
Okay. You've got your cords mounted on the dowel with lark's heads. Now we're tying the knot that's going to make up most of your hanging, whether you know it yet or not. The square knot.
I'm going to show you slow, twice, and then I want you to try it slow, at least twice, before you speed up. Everybody wants to go fast right away. Don't. Your hands don't know this yet. Let them learn it first.
What you need in front of you
Four cords. If you mounted two lark's heads per row like we talked about, you've already got groups of four hanging there. Take one group. The two outside cords are your working cords, the ones that do the moving. The two middle cords just sit there and take it. They're called filler cords, or some people say core cords, doesn't matter what you call them, they don't move.
The first half
Take the left cord. Cross it over the two middle cords, so it's lying on top of them, angled toward the right.
Take the right cord. Cross it over that left cord, then behind the two middle cords, and bring it out through the loop on the left side.
Pull both working cords tight. Not white-knuckle tight, just snug, so the knot sits up against your lark's heads with no gap. That's the first half of your square knot. If you stopped here you'd have half a knot, which lays a little sideways and isn't what we want, so keep going.
The second half
Now do the same thing, mirrored. Take the right cord, cross it over the two middle cords toward the left. Take the left cord, cross over that, behind the middle cords, out through the loop on the right.
Pull tight. That's your full square knot. It should sit flat, square, hence the name. If it's twisting to one side you did the first half right and the second half wrong, or the other way around, and that's fine, that's basically everybody's first ten knots.
So here's where I always mess up
Direction. Left over first, then right over first, that's a real square knot. If you go left over, then left over again, you get a different knot, a spiral one, and it looks fine for a while and then you look at it later and go, wait.
This is the part where I bring up the time I did this to myself for real. I was working a whole section of a hanging, probably two hours of knotting, cord always starting from the same side without me thinking about it, and I did not once check what I was making. Just kept going because it felt productive. Then I stepped back to look at the piece, the way you should every so often, and the whole section was spiraling like a barber pole instead of sitting flat like the rest of it. Two hours, gone. Had to pick every one of those knots back out.
The lesson isn't "be perfect." The lesson is step back every few rows and actually look at what you're making from a few feet away, not two inches away with the cord still in your hand. Don't fall in love with a mistake just because you already spent time on it. Time spent doesn't make it right, it just makes it harder to admit.
Practice before you commit
Grab a scrap length of cord, or use the first row you're not attached to yet, and just tie square knots for five minutes. Ten knots in a row, checking each one lays flat. That's the whole practice. It's boring in the good way, the same way running scales is boring. Your hands are learning something your eyes don't need to supervise forever.
Once you can tie one without narrating each step out loud to yourself, you're ready to do it for real down the row.
A word on tension
Keep your tension even, knot to knot. If you crank the first one tight and let the fifth one stay loose, your row looks uneven and it'll bug you later, usually right when you're trimming fringe and it's too late to fix without pulling things apart. Snug, consistent, same amount of pull each time. That's it. Nobody's grading this on a curve, but even tension is the difference between a row that looks intentional and one that looks tired.
And don't yank so hard you're fighting the dowel or your lark's heads start sliding. Cotton's got some give but it's not infinite.
Before next time
Tie a full row of square knots across your whole dowel, one group at a time, and then step back and actually look at it from across the room before you touch it again. If something's spiraling, better to catch it now than after you've built three more rows on top of it.