OK... I have lv70 Rogue, which is my first character ever, and I think it's now about time to actually know how to play with it... but I think I really don't :S I use combat spec and I'm not a pvp person.
I have been doing alot of instances again after a break but I think I'm like a noob there. I always make the smallest damage (excluding healer of course). I think my gear is fine, item level is a bit over 100 and I have lots of agi and stamina and critical if possible, but I think I don't really know how to play. I don't use daggers because I simply don't like them as much as swords, and basically all I do when fighting is spam Sinister- and Revealing strike and Eviscerate. In instances I tend to use Evasion and Adrenaline rush and apply poison and such but that's it on my move variety... (of course when doing quests I use stealth and stealth abilities but not in instances)

What are the correct tactics? What I should do to be more "powerful" as I barely can kill a mob with ~12 000 health alone -_-? Really, pls help me in mastering my class D:

I will give 10 points right away if you give me useful info and help...