Had my guys working on these last night. I use palm also in place of a cross with the rear power hand. Also worked tiger claws with the palm hitting first and ripping. I do a three strike combination on the heavy bag that goes low, middle, high tiger tear strikes very similar to a left-right-left hook combination found in boxing.
I also like to hold a focus shield and have them do palm strikes to gauge the power they are generating. Of course, this goes for lots of other strikes, not just palm strikes.
"The hero and the coward both feel the same thing, but the hero projects his fear onto his opponent while the coward runs. 'Fear'. It's the same thing, but it's what you do with it that matters". -Cus D'Amato