I am again with these horrible headaches, so I only will answer to the crochet afghan (although a much longer answer is itching to be written :-D) I am a huge fan of twisted single crochet stitch. I think it looks super neat and clean with a kind of roundish, cord like appearance.
I fear I already mentioned this stitch on several occasions and perhaps it is not new to you. Its nearly the same as crab stitch or reverse single crochet. But I prefer the twisted version.
https://stitchesnscraps.com/edging-crab-stitch-twisted-sc/