I always make sure to move my hands around a lot to make sure that I don't lock my arms, or put too much pressure on the same areas of my hands (causes tingly fingers for me). On my road bike, I move my hands around along the entire top bar and hoods, with some time spent with the weight along the outside edge of my hands. I only use the drops when I'm going over 26 mph, or when there is a big head wind.
I do something similar with my mountain/commuter bike, moving my hands around out onto the bar ends, etc.
I also like to have my bar high enough such that it just feels uncomfortable to lock my elbows.