just dont be pussy and dont bail, get enough speed and huck yourself down them, make sure you get a good hop for whatever your doing.. start small and go bigger
if your talking about actually riding down like firecrackers, i have no idea
if you're talking about double firerackers (like in the vid JD posted), its all commitment. i did a few on a 6 set today, they're really not that hard. just gotta hang on tight.
the key with them is to sorta lean back.
i did a double wheel firecracker down a 12 in my winter street vid from last year.
there actualy realy easy,u just gotta find a nice easy set to do it on first,preferably small stairs and then just work ure way up.