If you're doing non grouped pvp, and either want to get away quickly or get in another stealth attack (or 2). Spamming your Toggle Combat key (` default) and then spamming hide will allow you to get back into hide quickly.
I have down it almost instantly after being attacked from range.
If its a melee enemy, sprint away a little whilst spamming ` and H.
Only works in PvP not PvE.