You are going to Single Crochet (sc) through your blanket stitch around each block. This is your first round. I was using these vertical stitches to base my stitch in, but it is way easier to use the horizontal stitches instead (as shown above).
After single crocheting in each stitch, your first round will look like this. Watch this video to learn to Single Crochet. Disregard the chain in the video; you will be SC through the blanket stitch.
Next, you are going to do Double crochet around for round 2 and 3, refer to the original pattern here. I would recommend just doing a simple shell stitch instead, though. Since we are not counting the stictches, it is easier to just do the shell stitch or granny square row. If you are following this video do not chain 3 in between each shell only chain one. In the corners chain 3 in between shells.
Once you get all of your blocks crocheted, lay them out. I ran out of beige yarn and decided to swtich to green, which I also ran out of. So, after laying it out I decided to add yet another color of yarn to increase the size.
Next, whip stitch the columns together and then the rows. This way, you don't have to tie off after each block. Using a yarn needle, connect each stitch by moving from back to front. This works up really quickly.
This picture shows it better because the brown yarn contrasts the green and beige squares. It should look like this. When you go from one set of squares to the next, do a figure eight style whip stitch stitch to secure the gap.
Lay it out again and admire your work. It should look something like this!
I added a border to increase the size and make the blocks more coherent. Just do the same shell stitch, or granny square stitch around.
It is finally done. After this step you just cuddle up with it on the couch and drink some hot tea.