My favourite is a fan change (pass from front hand and catch with my rear hand) on the lead arm of an opponent's open stance opening out into an elbow strike to the head with the lead arm while the body does a straight arm bar with the rear hand, all while doing a crossover step to the outside. Turn the body and a forward trip completes. If the opponent resists by bending the arm you follow with a T-shaped lock (figure 4 chicken wing) to the same arm, moving in the other direction while sweeping in an O-soto gari like fashion (sorry for the JMA expression in a CMA forum).
I figured this out all by myself from the components, but I then saw an almost identical flow in a Bagua video I bought last week.
The beauty of the move is that you cannot reliably catch a hand, but brushing and catching is quite possible. Ask any catch wrestler. If you miss the elbow strike still lands and your hands are high.
When an opponent is extending a lead arm you must be wary of the rear arm which can wallop you pretty hard. Moving to the outside takes you away from the rear hand's power.
The trip falls into place, your feet are just there.
I managed to teach the follow on to a chap with only weeks of locking experience. It is a very simple technique to flow into, with an elbow to the face to keep it moving.
It actually looks vaguelly chinese.