This is a single sticking trick that you can get into from an
Idle or other similar type trick. When the handstick
hits the devilstick it doesn't give it any toss or flip. What you are
trying to with the devilstick is to tap it on either side to keep it in
a horizontal position so you can eventually balance it on a handstick.
When the devilstick is balancing on a handstick the center of it is
resting on the handstick.
In the picture I have the center of the devilstick balanced on the handstick.
What to do from here:
From this position, devilstick balancing on the handstick, I like to use the other handstick to hit the devilstick into a horizontal spin (like a helicopter). You can then do a few helicopter taps.