I put together this double crochet tutorial about a decade ago – hence the delightfully dated "fail" and "win" terminology. FTW! But man, the photos are clear, so I thought I'd republish it here on the blog.
The single most common question I get from my beginner students is why their double crochet swatch ends up looking like a trapezoid when they're trying to make a rectangle. The answer is that double crochet can be a total pain in the butt, because the first and last stitches of a row can be confusing to place when you're still learning the basics.
So here's a step-by-step tutorial with photos showing each of the confusing bits and walking you through where to place the last and first double crochets so your edges turn out straight and tidy, and you maintain a rectangle shape because you're keeping the same number of stitches in each row.
Where to Make the Last Double Crochet of a Row
Image 1: Here’s what it looks like as you approach the end of a row of double crochet. I’ve circled the tops of the stitches from the previous row that remain to be worked. It’s very, very common for beginners not to work a stitch in the top of the turning chain from the previous row. So in the circle are the final double crochet (rightmost in the circle) and, to the left of it at the end, the top of the turning chain.
Image 2: The arrow is keeping track of the turning chain, and I’m inserting my hook into the next double crochet.
Image 3: I’ve pulled up a loop in the double crochet. The arrow is still indicating the top of the turning chain.
Image 4: I’ve finished the stitch and the arrow is still pointing to the top of the turning chain. See how easy it would be to skip it? After all, it sort of looks like the edge could straighten out after a little tugging. Alas, though, it won’t.
Image 5: Ok, no more arrow. Here I’m about to insert my hook in the top of the turning chain. By “top of the turning chain,” I mean the topmost of the three chains. Notice how I’m using the fingers of my other hand to open that sucker up. It can be tight and/or awkward to shove your hook in there, but persistence pays. Your crochet is not precious – you won't break it if you tug.
Image 6: I’ve pulled up a loop in the top of the turning chain. It’s pretty apparent now that we need to work a stitch here to make the edge straight, eh?
Image 7: Here’s the completed final stitch of the row. There’s nothing to the left of it to stick my hook in, so I’m confident it really is the end of the row.
Image 8: Now we say to “turn your work.” This means to flip it around so your hook is poised to start the next row (in these photos I’m working right-handed, so at the beginning of a row my hook is on the right. If you’re a lefty and you crochet left-handed [hey, not all lefties do!], your hook is on the left at the beginning of a row).
Where to Make the First Double Crochet of a Row
Image 9: Make 3 chains. This is the “turning chain,” which serves the purpose of raising the hook to the height of the stitches you’ll be making. Since double crochet is a fairly tall stitch, most patterns say to “count the turning chain as the first stitch of the row.” This is because that turning chain takes up about as much space as a double crochet. Since we’re counting it as the first stitch, we work the first actual double crochet into the second stitch of the row, not the first. (If we work it into the first stitch, the edge will bulge out and look wonky.) The arrow is keeping track of that first stitch that we’re going to skip before making the first double crochet.
Image 10: This might be a confusing photo because of how the stitches move around with my hook. If it is, ignore it. What it shows is that I’m inserting my hook in the second stitch, and the arrow is pointing to the skipped first stitch.
Image 11: Ok, this is better. Here I’ve pulled up a loop for the double crochet, and the arrow is pointing to the first stitch, which I did not insert my hook into. At the very right, you can pick out the chains of the turning chain; see how they’re pretty much rising from that first stitch? That’s why we skip it before working the first double crochet.
Image 12: I’ve completed the double crochet and the arrow is still indicating the first stitch from the previous row. So even though I’ve only worked one double crochet, you can see it looks like we actually have two stitches in the row so far. This is why we count the turning chain as a full-on stitch. Now you just keep crocheting across the row, and make sure you work the last double crochet into the top of the turning chain.