I think keeping dosages as low as possible and ending the session early enough to sleep are of utmost importance. Also using saline rinses afterward can help with stuffieness (also a squirt of flonase before bed, but that stuff can really allow you to ignore your body's signals to take a break).
Definately take a few weeks off here and there. I feel like it is hard to keep drug use steady without increasing or getting jaded about the effects, and taking breaks helps keep the novelty from fading as quick.
How was your relationship with cocaine previously? I ask this because if you had a sizeable habit previously, it will take less use than the first time to bring cravings to that level, so be wary of that effect.