Wire walker Edit
The direction the string is wrapped around the tip is crucial. For a right handed start the string should come from the button, towards the thumb, then one wrap clockwise around the top.
Getting the top to tilt slightly away from the string before it starts to walk may help with tipping.
To finish, release tension and ... ???
Standard direction for the wrap is clockwise around the top (same as wire walker), then to the outside of the body i.e. toss the string over to the outside of the body. If you're not careful when raising the top for the start it may start to tilt, in which it may get ejected out the side on the way down. Not raising enough may cause it to strike your upper arm on the way down.