Determinate vs. Indeterminate: Cherry or miniature tomatoes are easier to grow indoors. Tiny Tim, Red Robin, and Patio Princess are good choices.
For each plant, use 5-gallon containers. Maintain drainage holes to avoid waterlogging.
Use compost or organic potting mix that drains nicely. Avoid pest- and disease-carrying garden soil.
Grow lights: Winter daylight is scarce, so use grow lights. Tomatoes need 12-16 hours of light daily.
The ideal tomato temperature is 65°F to 80°F (18°C to 26°C). Use a grow tent or space heater if needed.
Water frequently without overwatering. If the top 1-2 inches of soil is dry, water deeply. Mist plants or use a humidifier to moisten indoor air.
Encourage fruiting with a balanced tomato fertilizer (10-10-10) every 2-3 weeks.
Help hand-pollinate since there are no insects indoors. A slight brush or gentle shaking can spread pollen between blossoms.
To improve airflow and fruit production, remove suckers (small shoots between branches and the main stem).