Here's the secret of how I develop new techniques. When I come up with a new technique I use a sequence to try it out. First I test the foot by rotating it. Then I apply the new technique. Next I test it by again by rotating the ankle. Finally I analyze it, often with the client's input. So it is test-operate-test-evaluate. I use it with regular technique as well. It is called the "tote" formula.
If the technique is successful the muscles relax. There are 4 major muscle groups coming down from the leg. These muscles effect the tension level in the foot. Rotation gives you a pretty good idea of how much effect the technique has had. As far as feedback it comes in second to what your client says.
The "killer" combination is to do the TOTE formula and then get them up and walking after one foot. If the techniques are effective they are amazed at the difference.
Oh and this works to test your current techniques as well.