Step 1 - Counting:
While pedalling your bike, choose a foot and start counting every time it hits the bottom of the downstroke. You may count silently or aloud. I find that counting quite loudly works best, and helps clear busy multi-use pathways much better than an "on your left". Listen to the counting, and pretend that you are playing hide and seek and that you are 'it'.
Step 2 - Classify Yourself:
If you were one of the kids running off to hide, what would you think of the counting? Here are 5 main types of "counters" to help guide you in your cadence computation exercise:
Type 1: The Fair Kid
Type 2: The Competitive Seeker
If you are the Competitive Seeker type of cyclist, you are pedalling between 90 and 110 rpm, a good range for fitness and many other riding situations. If your goal was to really spin, however, you want to sound like our next Counting Type...
Type 3: The Big Fat Cheater
If you are a Big Fat Cheater (in a cycling cadence sense only, of course) you are spinning around 120 or even more... keep it up, and you will be the king or queen of spin, likely developing a smoother pedal stroke and sexy, supple leg muscles! Oooh baby.
Type 4: The Speed Freak
If your cadence count sounds like the Speed Freak, stop counting and get control of yourself and your bike, you maniac!
Type 5: The Confused Little One
If you sound like this, for the love of God, get off your bicycle and walk home if you can. You, my cycling friend, are drunk.
R A N T W I C K PS: While searching for hide and seek videos, I found this slightly disturbing tidbit, and y'know, why not share my mild discomfort?