Every year I start my own tomatoes...I have two favorite teacups with broken handles I fill with potting soil. I plant 20 - 25 seeds in each one 1/4 inch deep, evenly spaced. I cover each cup with a plastic bag to keep moisture in and place under a grow light. When the plants get their 2nd set of leaves, I gently place a sharpened pencil down along each plant, loosen the soil, and transplant into small disposable cups filled with soil. They grow in the cups until they are ready to plant.