I usually try not to wait until I notice a change in humidity to do something about my humidor bucause by that time, it means it will take time to get it to restabilize. You really want to maintain your moisture level while it is still in that sweet spot in my opinion.

and also do not over-moisten your oasis material (if that is what you are using)...if you do not over-moisten the material it will actually help maintain humidity levels by absorbing excess moisture if it is too high, and releasing moisture if too low.