Well I know anyone in the TdF is a whole lot stronger than I am, but I think anyone who can keep a light touch on the bars while climbing is either a whole lot stronger than I am, or has much lower gearing. I have to pull up hard on the bars to get enough leverage to pedal a steep hill.

And +1 on not closing off the airway. Getting out of the drops is probably the first thing I do at the bottom of a hill - before I downshift, even, often. The hoods give me the best grip and the widest open chest (I don't really like bars wide enough for me to use the tops).

Sticking out your tongue really opens the airway - they do it for a reason when they climb and sprint - but I haven't needed to do that on the bike since I took up running.