i dont usually stall freddy much. i try to stall foxy as much as possible because she always ends up rushing my door 3-4 times on 4/20 mode so its really difficult to manage her. i learned that leaving the door still open half a second lets me maybe anger freddy enough that she bonks and insta leaves the door so i can deal with the rest. i learned to count to 2 when dealing with bonnie and chica because they usually are off the door by the 2 second mark. so yeah i dont really know what else to improve. staring at foxy does nothing and ignoring her makes her rush faster.
edit : even with foxy i try to stall out her rush as long as possible when she is out her cove to buy as much time as possible.