Well, if you play the same stuff all the time then your lead will become stagnant. Try switching up styles of music to give you some new ideas, even if they're not necessarily styles you'd want to focus on, as a lead player you should be versatile. Resist the urge to be a one-trick pony.

Really switch it up and see what happens. Try new techniques and learn lead parts from different songs. For instance, when I started playing I really focused on playing Slash's stuff. I rarely worked on anything but learning his solos, after a while everything I started playing sounded the same too. I then learned other stuff from other artists for inspiration to give me a more rounded sound.

Hope that helps :p