If you spend a lot of time training in the gi (like me) then you've likely suffered some injuries to your fingers/joints. The grip game can be brutal at times and can even lead to time off the mat if bad enough. A training partner showed me this video recently and I found it to be incredibly useful. I'm one of those people that tapes their busted fingers and toes in a very inefficient manner which usually results in the tape falling off after 30 minutes of training.
Link for mobile users: http://youtu.be/xaNdxHisd4k
You can purchase tape that is already cut in narrow rolls or simply just cut it yourself.