One of the things that's really annoying me shooting on various DSLR setups is how the application of a little lateral force, particularly to the lens, causes my DSLRs to twist on their QR mounts (where they are attached with the 1/4" 20 screw). This can cause the camera to become loose on its support, requiring tightening, and can also cause the follow focus to disengage. It's damn annoying.
The issue is compounded when I attempt to "standardise" my QR setup. Some of my QR plates aren't able to natively attach via two screws to an add-on QR base. This means my options are to tap new threads into the QR bases, or permanently weld/glue the bases to the QR plates I'm adapting them from (which I'm reluctant to do).
I'm aware of "anti-twist plates" as one possible solution (between camera and immediate QR plate), but before I shell out cash, I was wondering if anyone was aware of a DIY solution to this issue, or could recommend something they paid for which solves it well. I'm usually using a 5D Mark II and a 550D, if that helps to provide some specific solutions.
How do you prevent the camera twisting around on one (or more) QR plates?