Start in the static start position, arms crossed. Lets say that your right arm is over your left. You are going to uncross your arms and then recross them so that your left arm is over your right arm. The devilstick will do a complete flip as the arms are uncrossed and crossed. The key is to keep a constant force on the devilstick with the handsticks as you do the uncross and crossing of the arms. The devilstick is now resting on the handsticks with your arms crossed, left over right. Then you just need to get the trick going back and forth in each position and it has a very mills messish look.
Another nice variation of this is to raise the devilstick over your head as you uncross your arms. When they are fully uncrossed the devilstick should be directly over your head.