yo dogg ill try to help.
ok first its good to be able to do mills and/or flares. i think u kno millz cuz i heard u once givin advice to sumone on it.
ok on coindrop u gotta drop on ur hands to forearms to shoulders to back.
get into the position that u normally see ppl drop into millz/flares/airflares/90s. with ur feet spread apart. ok U gotta whip ur left leg around back and to the right at the the same time leaning forward. just after u whip ur left leg use ur right leg to jump off onto ur hands. the small segmant of time that ur in the air u should be spinning but barely. the momentum of ur left leg should spin you and you shud roll onto ur shoulder then back.
also: knowing how to collapse in learnin windmill helps alot. a easy way to learn is to do millz normally from handglide position. then jump into sum facing the ground on all fours but with ur ass sticking out a little. and then do sum crouching low then crouchin, then crouching high. as u get higher and higher ur progressing in learning coindrop. and then do it from standing. alright man practice practice check out the coindrop guide in this forum. post a vid of ur progress. hope u get it. peace
