If you are just starting to adjust your cadence, it can take a few weeks to start spinning your legs a little faster to reach that sweet spot of 90-105rpm. The payoff in efficiency is worth it, but how are you going to get your body used to this new motion? Start with your feet.
Everyone knows how to pedal a bike – you just press down on the pedals, right? Well, sorta. With time lost at the top and bottom of your stroke, you will be lucky to be applying power one third of the time. Imagine your foot is moving around a clock from noon, through 3pm (maximum power) down to 6pm (no more stream). Try this to boost your cadence, especially when climbing. Pretend you are scraping mud off the bottom of your shoes. As the pedal comes to the bottom of the stroke, around the 5-6pm point, pull back to continue applying power from 5 to 8pm. You will engage new muscles and share effort between legs. It won’t double your speed, but can help give you a little boost, especially when you just that little kick to get over the crest of the hill.
One thing to avoid is too much ankle movement. Most cyclist ride with their foot flat to slightly pointed down. For a while I tried lifting and lowering the end of my foot to get a little extra leverage, and instead picked up some mystery strains. Biking ain’t running, and you can’t get a boost from pedaling on the tips of your toes.