Im currently using a lv 12 Imperial, and stealth tactics that work excellently on Novice don't do squat on Master, against the High Hrothgar Frost Troll. Not even on Expert. Im thinking its my race choice. What's a good race for an assassin on master? And what are some further techniques to employ? Im currently hiding behind rocks at a distance and sniping, it worked on novice, but then i wanted to test my skills on Master, the troll noticed me after the first shot and mauled me, i mean WTF how does that happen

At level 12 your Sneak won't be anywhere good.

You need the relevant perks and Smithing to get better bows.

You need the perks, ESECIALLY for archery btw. Try and get the bow damage perks up...it's the key to survival as an archer. And try to get the Bow Sneak attack perk on the sneaking skill tree ASAP as well.

And yes, smithing is quite important, especially to get better bows AND to upgrade your armor (you will die very easily without upgraded armor...so smith up!).

And race has very little effect on the outcome of your character, I'm playing as an Imperial thief which specialises in archery, and I've had no problems whatsoever (im playing on adept btw).

One thread is enough.