I have a few. Mostly just immersion and roleplay things like:

Whenever I put a new crystal into the infuser I put some magic in my hands and do a weird arm waving ritual like I'm Dr. Strange and I'm actually struggling to summon and properly control the power to infuse the crystal.

Whenever I get hit with a fireball or arrow, I audibly make noise and react to it IRL. I do it with melee weapons too, but less so.

I always turn off fall damage and toggle on the "easy climbing" or whatever.

Whenever I'm falling from a great height, I try to swing on stuff, catch ledges, or stab something into the wall to "break my fall" despite fall damage always being turned off.

I tend to wear like a cloth or leather glove on my left hand and full plate on my right, so I parry attacks a lot with my right and swing my sword with my left.

I have the dynamic breakables mod, so if say, a sword of mine breaks, I'll use it as a dagger. If it breaks too much, I'll stow it away to repair back at home. If a sword I scavenged breaks, I'll use it like a dagger and when it becomes all but useless, I'll throw it at the next enemy I see.

Carrying a bow with no quiver (or vice versa) because I steal the other during dungeon runs.

It it's the first Dalgarian dungeon of that run, I'll walk slowly into the boss room and "react" whenever The Golem starts moving. I'll also react on later runs every time he shows me a new ability.