I agree Catch... I carry a file for my egg patterns, bugs, and the few times every year I truly fish jigs, I do it there too. But as far as far as drift rigs go, I re-rig a lot. I keep hooks I get back from a snag, or after a fish, and every once in a while I will go through 250 or so hooks, and give them the once over with a file. Purely to save my cheapo self, some dollar bills. Pips cans work nicely, but when I stuff 35 pre ties in there, the removal gets hairy sometimes. So I have since switched over to pool noodles, cut into short sections.
But as Kodiak said, it is a really good idea to check your leaders often. I first check them after I tie a bait loop at home, and make sure I didn't wrap the last set too tight to bind the line being pulled through, and once again before I rig it, and every 10-12 casts around here, when fishing.