The more you keep your cam on Foxy, the more it delays her runs. Sound can you a lot, if you can hear the other girl's cues, and only use cams to watch Foxy.
Freddy giggles 5 times, before she is in the kitchen. After being for a couple seconds in the kitchen, she will attempt to go into your right door, so best to close it after hearing 5 giggles.
For the other girls, just wait to hear their footsteps, and then close the appropriate door (left for bonnie, right for chica).
The less you rely on Cams, the more power you can save.