For most roleplayers when they rolplay a character it is different than any one they have before. But if you are like me then there is something that you do for every character no matter what it is. My quirk is that no matter what character I play they alway have to have a dagger even if I know they will never use it. What is you roleplaying quirk (if you have one) discuss.
Like Brynjolf, I always collect books. I don't always display them on a shelf, but any unique or notable books will absolutely be added to some type of storage space.
Another one for me is always closing doors after NPCs, since they all leave them open. Especially true with the cabinet door to Delphine's secret room in the Sleeping Giant Inn... I always make sure to close the false back panel and the cabinet itself when entering and exiting. It seems silly to me to leave them open, as NPCs occasionally wander into that bedroom, where they would of course see the wide open secret door to the secret room...
One thing is that even though by far I am a powerplayer over roleplayer, I always try to sleep at least 5-8 hours a day. I also horde potions (primarily healing and magicka ones) but never use them.
One thing I used to do (not so much anymore) is give all my characters a favorite food. Maybe my barbarian likes fine wine and grilled steak with cheese, and my mage likes mead and raw venison. That type of thing.
Excellent question. When I first read this post, it took me a while. to think of something that all of my characters do. Aside from my hardcore rules (eat/sleep/ironman/etc.), the only commonality I could find was:
Once I enter a dungeon and decide to explore it, I will search every room, every corner, every part of the dungeon that I can.
Yeah i did pretty much the same with one of my Mage Characters, i made me a new home near Morthal with three Towers and then i filled the library with every book i found, soon i realized that the library is far to small to build a great collection and i also had some glitches with the bookshelves, sometimes books disappeared from the shelves when i activated it. So i thought that it isn't worth my time and moved on.
Normally i have one quirk which i tend to do with Assassin Characters... i leave one Deathbell on every Men or Woman i kill, i use it like a signature and it's my way to say I came, I saw, I conquered.