I usually try to keep my cadence between 90-100 unless I am doing a specific workout that requires low low cadence(ex. bridge reps in 53-15 to gain more explosive power).

A great way to get more comfortable spinning at a higher cadence is to incorporate spin-ups into your warm up. To do spin ups start in your easiest gear combination down in your drops. Spin as fast as you can until you start to bounce, once you start to bounce shift up to a harder gear. Continue doing this until you work your way through your gears or until you aren't bouncing anymore. Take a few minute recovery and then repeat. I usually do 4-5 spin ups during my warm up and feel that they have helped greatly with the smoothness of my cadence.