A few things before we begin. This blanket is fuzzy so I wasn't able to pre-make holes for crocheting into, and it already had a seam along the outside. I'd suggest going and buying the material at the fabric store instead of an already made blanket. The seam made the edging a little thicker than I would like and gave a bit of trouble on the corners. I really did attempt to pre-cut my holes, but I couldn't find them after I made them. I ended up just poking my hook through the material when it was time for each stitch with a solid guess if it was 1/2 inch or not. It looks a little homey, but still very pretty. There are some really great resources out there for finding ways to pre-make the holes. There is a place called Project Linus that sells a rotary blade just for these types of projects and how to videos.
Hook size: G Yarn: Caron Simply Soft Watermelon
To make the foundation row I poked a hole into the blanket starting an inch away from a corner. It is easier to to the corners as you go instead of starting on one. I did one single crochet into this first hole and then chain 1, about 1/2 an inch away from the first single crochet I made another hole, single crochet and chain 1. Continue this pattern until you reach your first corner. 3 Single crochets in the corner chain one and continue making your holes and single crochet chain 1 pattern.
Row 1: Single crochet every stitch, 3 SC in corner stitch, Slip to join, chain 2 do not turn work
Row 2: Half-Double Crochet every stitch, 3 HDC in each corner Slip to join, Chain 3 Do not Turn work
Row 3: *2 Double Crochet first Stitch, 3 DC next stitch* Continue until 3 corner stitches 3 DC, 5 DC, 3 DC Continue with 2 and 3 DC pattern Slip to join, Bind off.
I added a little extra by making an Crown Applique and adding it in the bottom corner. I got the pattern for that HERE. It's a free pattern by Sarah London, but remember that this is in UK terms and to either be familiar with it enough to transpose them mentally, or actually write the pattern using US terms before you begin. My crown isn't anywhere near as beautiful as hers, but I'm going to say that's lack of experience to make myself feel better. :)