I always die when i come across one.

Should i use unrelenting force and then just run away?

Ignore it.

Oh, wait, that's internet trolls.

For Skyrim... very carefully. Fire damage helps. On my warriors, I usually end up blocking, try to bash it and then strike before it hits me back. Also, always carry potions.

What are the specifics for your build? Are you a warrior, a spell caster, or a thief? What level difficulty are you playing?

Trolls regenerate so you have to hit them hard and keep it up. If you can, bring a follower or conjure a familiar. Conjuring an atronach is even better. Don't forget to use poisons (like slow or weakness to frost/fire/shock) on your weapon as a way to weaken the troll before using destruction magic.

Good luck!

When i bring a follower it always dies.

For the one at High Hrothgar, run towards the Greybeards' temple and let them take care of the problem for you.

fire and shield bash are you're best friends against trolls

Level up and get tougher,Trolls are tough creatures for lower level characters.

yeah, my bad. I didn't think of that 'cause I don't use followers. Hey OP - don't forget any Shouts you have.

Hoard healing potions.