To store tomatoes, keep them at room temperature, away from direct sunlight, and use them within a few days. Do not store them in the fridge, as this can cause them to lose flavor and become mealy in texture. If you have leftover sliced or chopped tomatoes, you can store them in the fridge for up to 2 days, but it's best to use them as soon as possible. Do not wash tomatoes until you are ready to use them, as moisture can cause them to spoil faster. Store tomatoes stem-side down, as this can help to prevent moisture from accumulating around the stem and causing the tomato to spoil.