Replying to Switch 540

okay i got my 5's down and i was working on switch on smaller jumps to get the feel for switch. just the other weekend i was working on switch 1's to get the feel of hitting a big jump switch. and i got that down. but i am afraid that if i start the rotation to soon then i will catch an edge and eat some shit, so i start rotating for the 180 midway through im in the air. what should i do so that i can land the 540 but not catch an edge on the jump?