how i do it is,
get cp out, HOLD RT,
Hit A on something,
Right D-PAD Once,
Throw,
Grab,
Use,
repet,
lol
must hold RT the hole time, ;D

Although i hate this glitch with a passion here is a simple way to do it. Step 1 get a Care Package, Step 2 Hold Right Trigger, Step 3 Find something to (A) command climb, Step 4 on your way up press right D-Pad Once, Step 5 finally throw the Care Package if it is still in your hand. Now just pick up what ever you threw, use it and viola the care package should still be on your right D-pad. Now all you have to do is just repeat all the steps to do it again.


Now i know the post above me already explained it this way, but i made it a little more detailed.