Re: Stress-testing structure
static pushes to various points on the body (shoulder, elbow, hand, hip) from the side in a natural stance and then from the front/back from a more fighting stance and then similar sorts of things while walking, pushes to the front, pulls from behind, pulls to one leg, etc. We'll also do variations of push out and more live grappling-y drills. There are quite a few variations on all these really.
When the opportunity is there I'll do some of these same things in classes, but I aikido them up for familiarity doing the pulls/pushes from ikkyo, sayu, etc.
I also try to replicate most of these stuff alone using various stretchy bands, yard equipment, etc.