On "Stay Strong" I used #5 pearl cotton and a #1 crochet hook. I made two of these (one for a friend) and learned that it's easier to chain stitch the length you need to completely encircle the finished piece . . . don't cut the end off . . . attach the chain around the seam of the piece and then begin crocheting the trim in each chain stitch. Much easier than stitching the complete trim and then attaching it only to discover that it's an inch too short!
Once your chain is attached slip stitch (Sl st) in the first chain loop, single crochet (sc) in the next. In the third loop of the chain: double crochet, chain one, double crochet again (dc, ch, dc) in that same chain loop. Single crochet (sc) in the 4th and slip stitch (Sl st) in the fifth . . . continue this all the way around. Somehow it came out even for me, but this may not be the case for you. If you start this at the bottom, it will most likely not show when you finish up there.