I used what’s called “roving yarn” (I think, it’s been years). It already looked kind of like dreadlocks so I thought it would be a nice and easy way to make a dread wig.
I had my mom crochet me a headcap out of a similarly colored yarn (not the roving but you could probably use that. Or a sock, I’ve tried that too and it’s not terrible).
Then I “tied” (Lark’s head knot) each strand to a similarly colored ribbon (again, you could probably just use the roving yarn, I like to be difficult). I made my strands twice as long as I wanted his hair because I knew I’d be tying it in half. Also, longer is better, you can cut it to the right length later.
Then I sewed it on. I took my first ribbon full of “dreads” and wrapped it in a very tight “U” shape for the top of the head.
After that I kept sewing on more ribbons with “dreads” on it. I kept sewing in a "U" shape, skipping a little space between the first row and the next because the yarn is pretty thick. I didn't need many ribbons to make it look full.
Once my wig was made, I added thin black string on a couple strands for decoration.
And threw some of it back into a ponytail.