You need to learn to ollie 360 while rolling. It's so much easier than trying it stationary. But, if for some freaky reason you want to practice your 360s standing still on the carpet in your living room, you can. It's legal.
Get rolling at a good speed, and shift your feet into the same positions you used for your ollie 180s. That is, you want your front foot right behind or over your front trucks, and the ball of your back foot right on the toe edge of your board, at the base of your board's tail. This is for a backside 360 ollie, which I recommend trying to learn first. For the frontside 360 ollie, place the ball of your back foot on the heel edge of the board, at the base of the board's tail.
You also want to bend your knees and wind up your shoulders, just like in the 180 ollie. Turn your shoulders and arms in the opposite direction from the one you are about to spin. Wind up tight, ready to explode.
