No need to trim off leaves. No need for epsom salts. Just good soil to which you add organic matter each year. Space the plants well to avoid crowding and wet foliage. And rotate the crops in the garden i.e. don't put the tomatoes in the same place. Also, there are fungicides to treat blight.

You can trim off the bottom leaves. This stops "nasties" from splashing up from the soil. However, there's no need for any more trimming for bush tomatoes.

Epsom Salts is a bit of a myth too. Really not necessary.

Linda