Growing tomatoes, my experience comes from the local horticultural college and Bristol University. I have grown tomatoes both outdoors and in a cold greenhouse, in both cases how many trusses would depend to a great degree on the summer, generally speaking no more than four outdoors and seven or eight indoors, then the growing tip should be removed. Never let sideshoots grow accept invarieties such as Tumbler which should be grown in hanging baskets. The idea of using tomato feed I.e. feed with a high potash content is to promote flowering, so needs to be fed before flowers appear and throughout fruiting. Irregular watering will lead to fruit splitting.
From my experience the smaller varieties of fruit give the biggest yields, they ripen much earlier and have many more fruits on each truss, these varieties such as gardeners delight and sweet- onehundred are sweet,if these are not to your taste and you prefer the plun size, beware of the old varieties such as moneymaker and Elsa Craig as these tend to “greenback”the flowering end doesn’t ripen properly and they have a hard core, try newer varieties such as Shirley. Unless you have a heated greenhouse don’t grow the very large type like Bigboy as these are unlikely to ripen before summers end.
When transplanting always bury them right up to the lower leaves, in this way they will develop more root.
To polonate all you need to do is tap the support stick from time to time indoors, outdoors when it is warm and still.
When growing tomatoes outdoors, always try to grow them against a south facing brick wall where they will get the advantage of the heat given off especially over night.
This is only meant to be a guide.
This year for the first time I am growing sweetmillion, I have just two in my small conservatory so far there are two flower trusses on each.
Keep going keep growing and good luck.