my first 3 was on a small ass jump i built in my backyard they are really not as hard as they seem you have to like they said above just look over your shoulder and it helped me to start with my arms wide going off the jump and then spin and for me it helped to get around faster
I've been having some problems with my 3's too.
I've narrowed it down to what I'm doing wrong.
Do NOT spot your landing until you are ready to complete the rotation.
Follow through the rotation by looking over your shoulder. When you are near completeting you're three, spot your landing and your body will natural bring your skis around and cease the spin.
For me, I tend to stop looking over my shoulder at about 180 and look down spotting my landing before I finish rotating. Thus causing me to eat shit on a sloppy 1.
Wind up. Throw a punch. Follow through. Spot landing. Bam.
I would have had this trick bagged last weekend but thanks to my still healing ankle sprain, I fucked my foot up pretty good messing up the 3 the first time.
Good luck and keep us posted!