Hybrid tomatoes are made by pollinating one true open-pollinated variety with a different open-pollinated variety. Open-pollinated tomatoes are pollinated by bees and insects. The offspring will be just like the parent tomatoes. New varieties of open-pollinated tomatoes are developed through selective breeding. Planting the seeds of hybrid tomatoes will not usually result in a new plant like either of the parents. Making your own hybrid tomatoes is time-consuming.
Select two varieties of open-pollinated tomatoes that have the characteristics you desire in the hybrid. One variety becomes the father because you are using the pollen from that plant to fertilize the blossoms of the mother tomato.
Remove the anther cone of the tomato blossom right before it opens on the mother tomato plant. Pinch the anther cone with a pair of tweezers. Snap if off; the petals will most likely come with it. The anther cone contains pollen and surrounds the stigma. The stigma part of the tomato blossom is attached to the sepal, which is attached to the ovary, which produces the tomato fruit when pollinated. The petals are bent back from the anther cone, stigma, sepal and ovary. Throw the anther cone from the mother plant away.
Cover the plant with cheesecloth so the exposed stigma won't be pollinated by insects. In 24 to 36 hours the stigma will be receptive to the pollen.
Remove the anther cones from the father plant. Lay on a piece of glass. The cone will dry out a bit and release the pollen. Or tap the pollen out of an anther cone still attached to the tomato flower on the father plant onto a piece of glass. You may have to slit the anther cone to get the pollen out.
Transfer the pollen to the stigma on the mother plant with your finger or a soft brush. The pollen should stick to the stigma.
Mark the hybrid flowers so you know which ones they are at harvest time. Do this with a piece of colored yarn lightly tied around the baby fruit.