Exactly, when you think something is over extended you take a small trade, and for me, most of the time it goes in my direction relatively quickly. Other times you gotta add and wait.
The ones you add and wait for usually are larger gainers, but I do prefer the instant gratification trades :p
That's why I use channel lines alot, when it's at a top of a channel, chances are it's coming back down, and if it doesn't, it's not going to run too much further so I'll just add to the position and even if it comes down to test where you initially shorted, your avg is higher and you can get out with profit there.