All you need to do is to take some pizza dough, either homemade or store-bought, and form it into balls about the size of a golfball. You then flatten each ball out into small round, leaving a slight lip around its edges—or, as I mentioned in the post on calzoncini, you can use a tortilla press to do the job in much less time. In fact, I prefer the tortilla press as it will make the dough thinner than at least I can manage with my hands.
As you form each round, fry it in hot oil until it is lightly browned on both sides, preferably olive oil but if that's too rich for you, vegetable oil, or a combination of the two, will do fine. Don't brown the dough too much, as it will brown further in the oven later on.
As they are done, place them on a rack (or paper towels) to drain.
Now it's time to get creative. You place these little fried pizza rounds on a cookie sheet and top them with whatever strikes your fancy—basically anything you'd put on a pizza, you can put on a pizzetta. A fried pizza round can also be made in bianco (without tomato) with cheese or other toppings.
Once you've assembled your pizzette, drizzle them with a bit of olive oil and season with salt, then pop them in a hot oven (200C/400C) for about 5 minutes or so, just until they warmed through and the cheese (if any) has melted.