What does everyone do to accomplish this? So that you don't hit plateaus and give your body something new to get used to.

I like to use negatives, drop sets, super sets, etc. to give my lifting more intensity. I also like to change things up, never doing the same thing exactly the same in each work out. So I might do pull downs one week, wide grip pull ups another week, close grip or normal grip pull ups another week. I like doing this just because I always feel challenged and never get used to any one thing.