My stuff is all on plain, flat bases and will be pretty generic when done - the typical gravelly grit with some static grass kinda fare. The only deviation from this is one unit of my Huntsmen that I have themed very much as scouts/rangers, in my head they operate very much in the montane wildernesses so I got some scenic resin bases that are woodland/forest themed and a set of slate/rocky themed ones too, and I've mixed and matched them across the unit. Even the scenic ones though I've opted for the more 'realistic' end of the spectrum and where possible I haven't used many that involve people standing on top of logs etc.
I get where you're coming from though, I've seen loads of Space Marines etc. stood atop massive chunks of cork before and I just think 'why?'...
The ones I find funniest is when the base seems to be an entire cross section of the ground beneath the model, with sewer pipes and everything else - unless it's a diorama where the sewers (and what lurks within) are an integral part of it, I just don't see the point. Does your army not look ridiculous when they're all mounted twice the height of your opponents' and how the hell do you get enough room to store them!?