How would I go about Tiling this Basement Bathtub wall?
Decent look is verging on "close as decorating advice" but if you have 3x6 tile and a 5-1/2" angle section, you trim the tiles on both sides to get 2 tiles centered on the section - or you find some tile that happens to be the right size and have an "accent" that's different from the rest of the tile job (some deep dark color, or that tumbled stone stuff, or glass tiles...) offsetting the rest of the stark white tile job. 

A section of herringbone seems to be a common "all subway tile" accent technique.