Indoor Cycling is a great opportunity to improve your technique without all the distractions you get when riding on the road.
You can spend a few minutes each session concentrating on your pedaling style, improving your posture, changing your position, or getting used to riding on the drops.
You can improve your pedaling by doing high cadence drills with beginning with 3 to 5 minute intervals increasing your cadence by 5rpm with a few minutes recovery in between.
Another exercise is to do one legged intervals which will probably take a bit of practice at first. The aim is to improve your pedal stroke so that it becomes more circular rather than just pushing down.
To help you develop a more circular pedal stroke one exercise is to loosen your shoes so that your feet can slide inside them. As your feet reach the bottom of the pedal stroke pull your heels into the back of your shoes. Then, as your pedal comes over the top, push your toes into the front of the shoes.