Guild Wars 2

Hey guys,
I was playing pvp the other day when I noticed that a large amount of the thieves I encountered surprised me out of stealth. I play power/precision thief and I keep getting killed because people see me coming. For example the two ways I know of to enter stealth are to steal with the trait that makes you stealth when you steal, and to use 5 with dagger in offhand. How do they get into stealth without anyone knowing?
P.S. im relatively new.

Weapons:
dagger and pistol (heartseeker trough blackpowder field)
Healing skill:
Hide in shadows
Utility skills:
Blinding Powder
Shadow Refuge
Trait:
Descent of Shadows (when taking falling damage)

Yup, leap and blast finishers on a smoke field (such as from #5 dagger) cause stealth.
http://wiki.guildwars2.com/wiki/Combo

If you’re new to the class, check out the video below as it will show a lot of combos that work with thief to stealth and port around:
http://www.youtube.com/watch?v=eUmrfBr1R5s

thanks so much guys!