Find an elementalist and target him raegardless of what your team is doing. He will be nearly useless, cus Im sure you can hit him at least once during his cast time unless he uses a really fast spell. If it looks like you may miss an important one, distracting shot is good insurance policy. As long as you keep targeting him, he will be nearly usesless to his team, and you will be doing *some* damage. Basically you are turning a 4v4 into a 3.5 v 3.

If there is no ele then you can try and do something similar to a necro or monk, but they dont cast so many long spells so it wont be as effective. Using a short bow for fast firing speed is helpful. Practiced Stance and Choking gas take up your elite, your prep, and your stance, so there not much more creative stuff you can do in the build except spirit spam and arrow shots.