Cork: Start by going for safety on the side you are spinning to (if you are spinning to left grab your left boot.) That should start to send you a little cork but not much, a wobble at most. After that start dropping your shoulder down to your boot (once again if you are spinning left drop your left shoulder.) Once you get comfortable with that start dropping your should down to your boot and back to your tails, just be careful since if you drop your should back too aggressively you may end up going into flat spin.
Bio: Don't think about the flip at all, instead think of doing a 540 and punching a midget infront of you. Make sure your right shoulder comes towards your left knee (if you are spinning left.)
Misty: Its like a bio but throw your shoulder down, pretend you are rolling over a table.
Rodeo: The only tip I can think of for rodeo is pretend you are trying to plant your feet on a wall beside you.
You should also try front flip and backflip before you try these, there is so much less to think of.
Hope this helps.