This is a very simple instructable that is relatively fun, but the only reason I'm even bothering to post this is because so many people ask me how I do it. Alright, let's get started.
Step 1: Get a Gatorade Cap
Yeah, just get a gatorade cap.
Step 2: Now Hold It Like This
Yeah, hold it like this.
Step 3: Aim It, Then Flick It.
Yeah, just aim it, then use your middle finger to flick it as hard as you can, while thrusting your arm forward.
I told you this was a simple instructable... I don't know why so many people ask me how to do this.
Try doing this at school, and have it land in the trash can, or see who's goes the furthest, or hit that poster with Einstien on it. Or maybe the teacher.
After a while of doing this, your middle finger may hurt.