Bike Forums - Am I doing it right?

I'm not much of a poster but I do lurk from time to time. I mostly am on the zx forums due to my other 2 wheel hobby. Ok, for the question; I was wondering if I am getting a decent workout. This winter I bought a catseye since I found out on here that I was a pedal masher. My knee loves me for it. So during the winter I spent time on the indoor trainer finding my comfort and high end cadence. Now that the weather is nice and I'm back on the road I want to make sure I'm shifting at the right times and spinning fast enough for a good workout. For the shifting; when I start to lose the pedals (not sure how to explain it,but when they start to go faster than I'm pedaling) I up shift as long as I can hold my cadence. If my cadence drops by 5 and it's getting hard to pedal I down shift. My average gears are the biggest up front and about mid gears in the back. That is where I run on flat ground. Keep in mind these are mountain bike gears, since that is what I am riding. I have 1.75 hybrid tires on it. My cadence for the shorter rides after work I try to keep spinning at 100, not dropping below 95 going uphill and 105 on an easier grade. Hills my speed slows to around 12mph. If it is real steep I'll get on the mid gear up front and down to the 2nd from the spokes and spin at around 110 to keep my speed. On my longer weekend rides 20 miles+ I'll keep my cadence at 90 to 95. Here are some pictures of todays ride with the map my ride app.

http://i863.photobucket.com/albums/a...ps46bbd298.png

http://i863.photobucket.com/albums/a...ps93e05f42.png

http://i863.photobucket.com/albums/a...ps7e93ac88.png