My LBS guro told me that I should learn to ride on my drops when I purchased my new road bike. I preferred riding on my hoods but he gave me some good reasons to ride on the drops which I can't remember now.

So, in order to break my habit of riding on the hoods, I started playing a game during each ride. Whenever I came to a nice flat stretch of road I rode in the drop position. I tried to see how much I could increase my mph or cadence during my "drop time" which made it fun and challenging. After a month of doing this, riding in the drops became second nature.