After time your decks WILL break, some things to keep in mind, land with your feet over your trucks, let them take te beating and spare your deck, also definately dont overtighten screws, i fucked up my longboard that way :(
Furthermore i dont think you can change much, definately go through your knees when you hit the ground, dont stomp too hard....
+there are quality differences in decks, maybe try bamboo or some other wood