Ravelry: Designs by Pat Ashforth and Steve Plummer - Woolly Thoughts
I’ve linked to a few already (1, 2, 3) but to save time linking to all of them just check out the Whoolly Thoughts page on Ravelry. Some amazing geometry/optical illusion crochet and knitting and I think all of the patterns are available to purchase for ~$5 a piece.
