Know when to stop adding nitrogen fertilizers.
Excess nitrogen encourages leaf growth at the expense of fruit. If you’re wondering why you’re not getting blossoms or developing tomatoes, put down the liquid fertilizer and instead drench the soil with a gallon of water spiked with a tablespoon each of kelp (granular or liquid) and Epsom salt.
The soil you’re using is also critical. My condolences now if you used nitrogen-enriched, time-released, chemical-laden potting soil. Clemson University Cooperative Extension warns against high levels of nitrogen because it can hinder calcium uptake and possibly be a contributor to blossom end rot.
Water the soil, not the plant.
Use drip irrigation or soaker hoses. Do not spray the plant with water. This encourages disease. Once the plant is established, try achieving a watering schedule that allows you to go a couple of days without watering. It’s better to water deep every 2-3 days than to water the surface every day. Tomatoes in containers should be watered until it’s draining out freely and then wait until the plant needs it again. Over-watering is a common misstep.