Use your machine of choice to chop up your parsley (or chop the old fashioned way with a knife - it takes more time, but you'll end up with a slightly nicer, more consistent end product), drizzling about 2 tablespoons of olive oil in as you go (this helps bind the parsley together for pressing into the ice cube tray).
Measure a tablespoon (or preferred measurement) of the chopped parsley and place it into one of the ice cube tray compartments to use as a guide for filling the rest of them with approximately the same amount (I used the pink flower-shaped ice cube tray from Ikea - only $1.99 and cute as heck!)
Press the remaining parsley into the remaining ice cube tray compartments.
Pull out the tray and pop your little parsley shapes out! Aren't they cute? Now just put 'em in a Ziploc bag and store them in the freezer until you need them.