Downstream bow technique
This is a handy trick for getting a fly unsnagged. I initially mentioned it in the recent barbed/barbless thread, but will take a hint and start a new thread on the topic.
Zero and ezamora, it sounds like you've already got the idea. Come to think of it, this really only applies when fishing downstream. Once you find that you're snagged, and you think its hung on a single object (as opposed to being lodged in a brush pile) follow these steps:
First- stop tugging, no need to plant the hook in the snag deeper.
Second- flip a roll cast toward the snag with all of your excess line.
Third- pull some extra line off the reel and feed it through the rod so you have a large bow in the line pulling away from the direction the fly was going when it got snagged. (size of bow needed depends on depth of snag and current speed. slower current/deeper snag= bigger bow)
Fourth- (assuming the bow itself doesn't pull the fly free) give the line a powerful strip and sweep the rod away from the snag. (the surface tension will change the angle of the pull so that it should dislodge your fly)
Finally- Once the hook is free, get that line stripped in quick so the fly doesn't have another chance to get snagged while dead drifting downstream..
I'm not saying that this technique always works, but I think its generally worth a shot. Especially when you're hooking fish near the snag and don't wanna go trudging through that water and spooking all the fish. Its also a nice trick to have in your reportoire to get a fly loose when wading to the snag to free it is not an option.