Partly drilled holes in the surface give you bird's eyes/raindrops when you do your final squish. Partial cuts into the surface with an angle grinder give you "waves" in your parallel lines when you squish. Can't beat Nick's thread for producing ladders. Twists are, well, twists. Anything that upsets the surface prior to squishing will show up as some kind of patterning, but remember, the more grinding you do after, the more the pattern will revert back to parallel lines. (Unless you're using the Ruffles to Dorito method).
Then there's all the Mosaic stuff which i'll leave to others with more experience to discuss