I've found that doing some work at the gym on a trainer equiped with a cadence and watts readout really helps out. You can set the resistance to a certain level and then bounce back and forth between cadence and watts to see how fast you are spinning, along with how much power you are putting down. It’s helped my average quiet a bit. After awhile you know what a certain cadence and power output feels like and learn to stick to a challenging but maintainable level.