Well lets be honest I've been using FPSC for quite awhile and got use to the limited prefabs and the sucky light mapping.
The problem I have encounter while building my game is that most of the times it looks like light mapping fell out of the sky.It looks extremely bad.
And I see some people only tend to make use of only one or two lights and that's not a good idea.And then I learnt the wonders of using a few smaller ranged lights to brighten up the maps.which works wonders.
Red lights is a big no no.Stay away from them if you can this engine can not soften the light to exceptable levels.However they work good like the above screenshot if you have them ranged.This also depends on what textures you use them.
I also see people make use of only one layer to build a single floor don't...try and use two layers to build a single floor it looks better and objects in your level doesn't look so pressed in.
How I place objects in a level have a look for your self.I can't explain how I just do it.If any one disagree's with me please post a comment.
As for tips.Don't stare into the sun.
Oh and yes I do like my mini gun.
Here is a screen shot which shows How I do light mapping.
