* The beginning of each round always begins the same: (Chain 2, 2 double crochet, chain 3, 3 double crochet, chain 1) in the corner you choose to begin the next round. This is done the same as the rest of the corners if you can remember that the first chain-2 counts as the first of those three double crochets and that’s why you’re only putting 2 double crochets in there after the first chain-2.
* Each following corners will be worked the same: (3 double crochet, chain 3, 3 double crochet, chain 1)
* In each chain-1 space from the previous round you will add: (3 double crochet, chain 1)
* The chain-1 after each corner and the chain-1 after each 3 double crochet you work along the sides add an extra chain-1 space for you to put another (3 double crochet, chain 1) in the next round. That’s how your square/blanket gets evenly larger.
At the end of each round, you will join with a slip stitch, and if you are using the same color you will slip stitch up to the corner. If you are changing yarn colors then you will fasten off after you join with a slip stitch and join the new yarn with a slip stitch in the same corner you would have slip stitched to. (Though I’m pretty sure you can join the yarn in any corner and it’ll work out the same, so if you set it down, walk off, and then forget which was your ending corner, that’s okay.)