I've seen a few threads where people are struggling to light complex exteriors/interiors and I think it would be nice to share some tips/tricks to make the whole thing easier and faster. I'll start.

Here we have a basic scene with one 'Sun' light and IDL. There are no textures for faster rendering and so that the issues don't get hidden under nice texturing. It has almost all the artifacts you run into with IDL (in all  cases open the pic in a new window to see full size, where applicable)

 

And these are the render settings.

Yes they aren't particularly high or optimized but they render fast (about 30-40s) We could pump them up to get rid of some of these artifacts (but not all) or disable IC altogether and do a really long render... but is there a better way ? Keep reading to find out :P