For me it depends on the bike.
X4, I'm virtually always in the drops. It feels weird on the hoods as the brake levers are on the downward portion of the bars. When I'm on the hoods I have this uneasy sensation of going over the front of the bike.
Ti Mega tube, I have a set of Cinelli Spinacholi (?). I'm getting to really like these things. In this case I rest my forearms on the top of the bars and I rest my hands on the Spinocholi's.
Carbon Cross, virtually all the time on the hoods.