Standard ones stated.
But Positioning is a big one... I see so many teams play 2 players back (On their Serve) I had one partner do this as well and I nearly had to walk him up to the net before I served.
You give every angle away in that position.
Net guys never poaching. at least take a step or two to the middle and get in the returners head that he is going to have to pass you...not just standing there waiting for the point to start.
Hitting Chip shots...this is doubles the net guy is licking his lips when he see's you chip shot...anyone with even a little speed will track it down for a put away volley.