Some tomato varieties fruit all at once and you have a glut. That can be great for making sauces for winter pastas. Other types spread their productivity more evenly over the season.
If you know the type of tomato you have, you can try checking its name against a description on the Kings Seeds website - kingsseeds.co.nz - to see whether your plant is determinate or indeterminate. The determinate ones ripen all at once.
Cherry tomatoes are indeterminate, so you need to keep them well-fed and watered so they'll keep producing for as long as possible.
If tomatoes dry out, you won't get a good crop. And if they get too much rain, they can get powdery mildew. Don't water them during your lunch break in the heat of the day. Try not to get the leaves wet, as diseases like blossom-end rot can ruin the fruit.
Check they aren't overshadowed by climbing beans or corn, because tomatoes need lots of sunlight. Watch the little yellow flowers and, when the fruit begins to set, you could reward them with liquid fertiliser, such as Tom-A-Rite or blood and bone, sheep pellets, potash, or seaweed "tea".