add weight anyway?

Ok people, lets hear what you all do. I like to work my reps at percentages of my 1 rep maximum. I increase the weight as I go and decrease the reps. However, I like to get an extra rep or two on my last set before i jump my weight up. I was wondering if some of you jump the weight regardless in order to add more stress, especially when you find yourself sitting at the same numbers for a while.