Start with doing the idle. Give the devilstick a little extra spin when tossing it back to the right side. When the devilstick hits the right handstick stop it so that the devilstick is parallel with the ground (the stop). Don't toss it back to the left side. With the devilstick still horizontal, take your left handstick, bring it under the left side of the devilstick, and do a normal hit (the go) to the right hand where you can "stop" it again.
When you stop the devilstick with the right handstick, be sure to move the handstick out of the way. The devilstick will then hang in the air for a second. It will also prevent it from looking like you are just catching the devilstick on both handsticks during the stop.
A nice variation to add to the Stop & Go is to do a Handstick Flip with the handstick doing the "go". If timed correctly, the handstick will be flipped, caught, and be right under the devilstick for another "go" just as the other handstick does the stop.
Video of stop & go with a handstick flip: