even for a 5 or 7 you don't really need to whip your arms around madly into the air like Brian Botano.
I hold my outside hand (the direction I plan on spinning) in front of me to ensure that my weight is forward and all. In reality, a little momentum behind your shoulder and keeping your head going where you want your body to be is all that you need to get the spin around.
Look, the most important thing I could tell you with 360's is your stance and what you do BEFORE you are in the air.
If you set yourself up wrong then you are most likely to land wrong.
If a 360 is a new trick for you then you most likely are going to be concentrating on what it is going to take to get the spin around and land it. But don't forget that you HAVE to start the jump off right.
One of the most common mistakes is to lean backwards as you are going off the jump and then try spinning as you go off the lip.
If you are doing this then you'll feel awkward. For one, carving off the jump too much is going to set you off balance.
And secondly a poor stance (leaning back) means that you will most likely land backseat on your skis.
To fix this follow this simple process.
As you are coming up to the jump you need a strong stance.
Bend your knees
Press your shins up against your boots
keep your hands in front of you
when you come to the lip,
Pop up
then spin.
To spin, keep your shoulder moving in the direction you want to spin.
Where your head goes your body will follow, so keep your eyes looking where you want to go. If you are not quite getting the full 360 spin around then it could be that you stop looking over your shoulder. Keep it going until you are at 360.
You will find that spins move much more flowing if you tuck up your knees..
once you get the feel for a 360 start to tuck your knees up.
For the first few times you may want to throw your hands, and make sure that you try it on a jump that you are already real comfortable with.
That's it. Most important part is HOW YOU APPROACH THE JUMP. a poor stance will probably result in landing backseat.
Hope that helps,
now go stomp it.
Eat. Sleep. Breathe. Ski.