Cycling drills: many people don't think about form that much on the bike but it's an important aspect to be a better cyclist. Here are 2 drills I try to do most days I'm on the bike.
Single Leg: In an easier gear, unclip one leg and hold it out of the way of the pedal & crank. Ride for 30 to 60 sec with one leg still clipped in, then switch. Do this 3x each leg. As you drive your leg down and through the bottom of the stroke, visualize scraping mud off the bottom of your shoe. On the up stroke, it's not that you are trying to add a lot of power pulling up (your knee isn’t really built to handle that force), but rather work on lifting the leg up and over the top. Here, the idea is to get used to having the leg lift itself up (from the hip flexor) so that when you are riding with two legs, the other leg's power isn't used in part to lift the leg. Finally, as you finish the up stroke, drive your knee toward your handlebars and your foot up and over the top. Any inefficiencies in the top and bottom of your stroke will be felt as decelerations or "dead spots" and should be smoothed out.
Super Spins: In the easiest gear you have, you want to spin your legs as fast as you can. If you have a cadence sensor you want to see really high numbers, ideally over 160. Fairly quickly, accelerate from your normal cadence to as fast as you can go until your butt starts bouncing on the saddle. Try to keep it glued to the saddle and maintain that cadence for 15-30 seconds. If it is bouncing too much, back down the cadence slightly. Take about a minute rest and do it a second time. The idea here is that you are trying to increase your comfort level at higher cadences. This drill also helps you spin efficient circles. The faster you can spin with low resistance (you could even do these drills going downhill) without your butt bouncing, the more efficient your pedal stroke will be.
As with any drill, these are exaggerated motions and not something you will do for a long time. Learning new physical skills, we often take the idea to the extreme in order to push the body, so the new behavior doesn't feel quite so different. Much like you would run fast 400 meter intervals in preparation for a longer race at a slower pace, these drills will help your body adapt and become a better cyclist.