DO NOT hold the stick firmly. It needs to be able to bounce and vibrate. I'm not a drum player but I played around with the snare drums when no one was looking in middle school lol.
Ill try to give a little input here being a drummer for ~3yrs Mustang is correct, hold it semi-firmly so that it has a little wiggle room in your palm and when you wanto do rolls hold it just a little looser holding it with just your thumb and index finger with the rest loosely curved to form a boundary of sorts about half an inch of the stick so that when you strike the drum it will bounce and hit the head a second time on its own, remember its all in the wrist.