A bigspin involves doing a fakie 360 shuvit body varial. To do this, ride along fakie with your feet setup for a 360 shuvit. Pop the shuvit and as it starts to spin, you must turn a 180 body varial in the same direction as the board is spining. You should have finished doing the body varial just as the fakie 360 shuvit finishes so you can catch it with your feet.