A simple way to pit olives for your Greek food is to smack them with the flat of a large knife; the meat will then peel off the pit easily. If you're planning to use a large number of olives, roll over them a few times with a rolling pin. This will loosen the meat from the pit as well.
If you want to pit an olive for your Greek food without smashing the meat, the rolling pin won't do. Instead, try squeezing the olive; the pit might pop put (this works more often with black olives than green ones). Otherwise, you'll need to cut the olive lengthwise and peel off the meat.
The best way to crumble feta cheese for your Greek food (assuming you can't find it pre-crumbled) is to run a slice under cold water for ten minutes to firm it up and clear off the brine. Then break it up with your hands or the tines of a fork.
