Don't forget about custom grid helper objects, they can be positioned and aligned like any other object. This helps when working vertically in perspective view. It's a pain in the ass to always switch from pers to front or left view just to use the vertical grid. Grid objects can be found on the Create Panel > Helpers Tab,…
@Adam, I think you're right 8:1 is probably more in keeping with games today and especially the next round of hardware which artists should prepare for now. With 8:1 you just need to be mindful of the dreaded down resing (at least in production). Don't draw 1px lines or use tiny fonts on a larger sheet that might be cut…