If it doesn't work ... change it

Even a very well-honed and skillful technique won't necessarily work on everyone.  There are some flexible people in my class who certain joint locks won't work on; others are fairly impervious to strangles; various throws are more difficult to pull off against heavy, short or tall partners; particular pressure points are "dead" on some people.

So:

1. practice with many partners;
2. learn variations;
3. learn to flow into other techniques.

If a technique doesn't work, work on it and improve it, and figure out what else it sets up.  I haven't met anyone yet who is impervious to all techniques.  When I do I'll ... run away!