I have lots of 'em.

I don't pick flowers inside of city limits, or sometimes even the outskirts. That includes exposed places like Ivarstead or Morthal. Both of those locales have nirnroots to be plucked, but i don't. I still harvest any chicken's eggs and wheat, though. Pretty hard to acquire otherwise.

I don't strip "setpiece" dead bodies. Like in Ustengrav, there are a few already dead bandits and mages. I'll take their gold, gems or what-not, but will not strip them beyond armor/robes and boots.

The cell that contains my abode, Lakeview, is special territory. I never pick the nearby flowers or mine the nearby ore vein. Whenever I arrive home, I wish to see a bit of pristine landscape around it. The little pond to the south is fair game for dragonflies and fishies, though. They come back rather quickly.

I don't strip interior cells of decor, either, even if I am allowed to. When I visit these places, I want some atmosphere. Unless it's a dungeon... that's fine. But not the Bard's College, or Jorrvaskr for example.

When I'm out on a Bedlam mission for Delvin Mallory, I still don't rip off stuff lying in the open... I only raid containers.

I try to collect butterfly wings by hand, rather than shouting FUS, because I find that the wings clip beneath the landscape too often when you let them drop onto it. I get really irked if I don't get both wings from a dead butterfly/moth.

So yeah, I'm nuts. And I express it when I play my games. At least it's a healthy outlet.