It's easiest to use tomato plants from the nursery. The employees can tell you which tomatoes grow best in containers in your area. Choose the right pot for the tomatoes you want to grow. For a miniature tomato, choose a pot that holds one-two gallons of soil and additions to the soil. A cherry or patio tomato plant needs at least three gallons of soil.
Large tomatoes require five gallons, and seven is better.
Make sure the pot you pick has good drainage. Use broken ceramic or rocks to cover the drainage holes. Pick a good, all-around potting soil. You don't need to buy a special potting soil for vegetables. Any well-rounded soil will do.