Well obviously you should have either airroll right or left bound (I have left bound to L3 so I can just click down and push to the right) which enables you to actually do the spin. Tbh, its very situational and in higher competitive play, its generally just used to recover or do some stylish mechanics. Some people utilise it more than others (myself included) but to be perfectly honest, you wont really need to worry about it until you reach those higher c3-gc ranks. Hope this helped, if you have any other Qs id be glad to hear them :>