I like to find a middle sized wall and just lean backwards into it.

I can crack soooo many things.
Both ears, (SUPER LOUD and nobody can see how I do it. I dont know either. I'm the only one I know that can)
My jaw.
My neck.
My upper back,
lower back,
elbows,
wrist,
thumb,
that one bone that connects the bottom of the thumb to the hand,
all my fingers,
Both sides of my pelvis,
My knees and all my toes. xDD