Watch a tutorial on FNAF 1 strategy and use the exact same thing. Only use cams for Foxy, dont hold cam open, just flash it so you can see Foxy's progression stage. Freddy will laugh 5 times, the fifth laugh is the final position, close the right door on the fifth laugh. Another Freddy laugh will resemble Freddy moving 1 room back, open the door. For Chica and Bonnie only use the door lights with quick flashes to see if they're at the doors. Like I said avoid cams for anything but Foxy, even then you have something like 15-30 full seconds before Foxy goes into the hallway attack stage, so dont spam the camera and waste power. It's tricky at first but once you get used to it you can beat every night in a single playthrough, including 4/20 mode.