Being smooth and precise in the air?

What do you think is the greatest contributor to the above in all disciplines?  How much is experience in the air and knowing how to fly your body, and how much is other things like body strength, natural talent, and gear?

#1 - Experience & training. 

#2 - Kinesthesia & proprioception: https://thesensorytoolbox.com/kinesthesia-proprioception/

Some people have better proprioception. Others have better balance (which is part of it). Still others have better spatial perception, which comes in handy for formation work. 
Gymnastics & dance can help too. I've heard it said that ballet dancers often make excellent skydivers.

I would put strength well down the list. Flexibility is more important.

And other than fitting properly and 'appropriate for the activity' (don't wear a suit with booties when trying to sit fly - trust me on that one), I don't think gear is a factor.