noob question: how to ensure pollinated flowers form tomatoes?

[franzb69]

is there some special way to help ensure tomatoes to form tomatoes from pollinated flowers?

i always get tons of flowers and i pollinate them with an electric toothbrush, some tomatoes form but never goes through.

is it coz of the rain? or some sort of nutrient deficiency?

thanks for everyone.

here's one of my problem cherry tomatoes, just one out of the whole flower cluster formed. seeds from pinakbet