It really depends, on a lot of things. 1st, are you low health, if so back. If you can clear more and can safely do it, I say go for it. Do you have a good gank. Keep in mind I don't necessarily mean a kill, a kill is good, but can you either get a kill or force out enemy summoners and them out of lane allowing your laner to stay in farm. If so, gank. With the reset timers being what they are now in the jungle, I typically push it as long as I safely can before backing, just so they respawn for a 3rd time even quicker. Especially this season it is important that you keeping farming the jungle between ganks for gold and exp.
Out of curiosity, who do you normally jungle with?