After I started solving my 3x3 cube for a while, i always wanted to know how to effectively mix up my cube. I learned and now I'll teach you. I was always bored when trying to mix it up, but now it takes only five seconds to mix it up!
MATERIALS: A rubik's cube and 5 sec. : )

Step 1: How to Mix Up Cube

1. hold cube with 3 sides facing you.
2. hold cube with pointer fingers on back, top rows of cube ( shown in pic.)
3. hold other fingers as shown
4. hold thumbs on front, bottom side, in the middle rows as shown
5. pull right or left index finger towards you, turning the side face of cube.
6. repeat with left (or right finger, depending on which finger you pulled 1st)
7. repeat for a total of 4 spins in each face,
8. move whole cube so another 3 sides are facing you and repeat
9. with practice you will mix it up faster and faster, thus taking only 5 sec. to mix up.