A vertical "X" with your rib cage:
Squeeze left upper back to send rib cage up and to the R. Come back to center (make sure your center is good posture with both pelvis and rib cage... and while we're at it, where are your arms and hands? ;) )
Squeeze right upper back to send rib cage up and to the L. Come back to center.
Squeeze right upper abs to send rib cage down and to the L. Come back to center.
Squeeze left upper abs to send rib cage down and to the R. Come back to center.
You can lock to these branches of the "x" and then lock back to center, or pop and relax back to center.
Now for the vertical rib cage "t" (it's like a lowercase t with no tail):
Squeeze upper back for a rib cage lift. Come back to center (posture check!!!)
Squeeze right serratus (under your arm pit) for rib cage slide to the L. Come back to center.
Squeeze upper abs for rib cage drop. Come back to center.
Squeeze left serratus for rib cage slide to the R. Come back to center.
Lock these, or pop them, as with the x.
Now try to the x followed by the t. Pop one and lock the other. Alternate.
Add more spokes by combining the x and t so you're hitting 8 branches as you go around. Can you keep them all sharp and clear?