After a decade of this kind of treatment, Darrell's Tulsa, Oklahoma dirt grows some fine 'maters. Just the experiences of gardeners. Darrell is one of the finest, and his common-sense and sustainable tips are among the best. Water thoroughly to encourage the roots to seek water and nutrients deep in the soil. Soak to at least six to eight inches.
Soaker hoses are ideal but unless attached to a water meter, the amount supplied is guesswork.
Gallon containers with a hole in the bottom sunk between each tomato plant works well. Fill with a water hose twice a week. This method also gives you a chance to inspect the plants while watering. If you use an overhead watering system, water early in the day to allow the plants to dry out before nightfall. The nighttime dew is enough for the plant to cope with, and foliage too wet overnight may help some diseases.