yeah it would help to get good at sliding unnatural. i learned on a nice wide battleship box, you could do it on any kinked box, or flat box, just find one that you wont get screwed on if you mess up. i learned spinning backside,  when you get on make sure to get pretty low, bend your knees a bit so you can jump easier, then jump and jump pretty high, and just spin 180 and commit and land with a wide stance. it would be alot easier to go switch, get on natural, and spin frontside.