I find that dropping in little-known real world deities into a D&D setting can be really helpful in developing depth, as they have complexity and baggage not often present in the cut & dried standard D&D gods.

Seriously, that's such a good little hack. It's something a lot of folks don't bother with (much like we don't often represent polytheism in a realistic way), and having those little quirks that can only come from real people believing weird stuff is a huuuuge benefit to getting folks to see the Patheon as more than just one-dimensional cutouts.