Thank you so much Steven!
I really like this exercise
A drill that I was taught at an Aikikai school was called leading the blind. What you would do was to have one person close their eyes and the other would guide them around the mat, moving uke in various directions including circles. We would finish by lightly, at first, throwing uke with a front or side throw. The idea here is to see if you, uke, can sense the movement and flow with it.
and think I'll give it a try tomorrow night (as long as we don't have too many people on the mat). I could see how this would require uke to really relax!
Do you have anything like this as nage?
One thing I've been trying lately that seems to have a bit of success is to have everyone line up against the wall and extend one arm out in front, knife blade of the hand to the wall. Then you lean into it with a good amount of body weight. If you straight-arm it, all the energy goes into the shoulder; if you bend your arm in too much, it becomes too much stress in the biceps; everyone has to figure out where they can comfortably lean in on their arm with a slight bend without tension going into the shoulder. Of course this is working for extension and pushing forward connection as uke (as well as nage), but it doesn't address stiffness in other forms.
Other suggestions are extremely welcome!