Read KSH's post "Listen up new riders, learn to spin and save your knees" that is on page two of New Riders (this particular discussion group).

That has phenominally changed the way I shift, and I'm not a new rider. Do you ride paying attention to cadence? When I rode my aluminum frame bike I rode a cadence of 85 to 90. With the new carbon fiber and learning to spin I ride 105 to 110, which to me is incredible, and is so much easier. I literally put to test the spinning theory: I pedal in an easy gear until I am going so fast my butt is bouncing out of the saddle, then I shift to a harder gear, and as soon as I am bouncing I shift up again, and so forth, working to keep my cadence at 105. Also, since I have hills I have to plan a few of them and make sure I have something left to shift down to on the ascent when it gets hard. Since I use a Flight Deck computer it makes it easy to see what I have left.

My method years ago when I was mountain biking and then when I first started road biking was to ride in the biggest chain ring and as hard to pedal as I could stand. However, now that I'm riding long distances I've learned to do just the opposite and incredibly enough, over the long haul, I am actually faster and more efficient.

BTW, I just went from a triple chain ring to a double chain ring when I got the new bike. I've not missed the triple at all.