I always think of themeless puzzles with a grid shaped like so as a winding river. It's also pretty easy/tempting to split this into three puzzles while you're making it (upper left, middle diagonal, lower right), which is why I've put the two long entries at 12- and 13-Down to open things up. Hope you enjoy it.
Here's a nice article about Mike Shenk, one of the Crossword Jesuses. There's not much about Mike online, at least as far as I can tell, so it's good to see at least something out there. This is hopefully the start of many more.
Share the puzzle. New one on Thursday.