Hi Strawberry . . . my homemade tomato soup doesn't taste at all like the canned condensed kind, but here goes.
I prob'ly use about equal amounts of tomato juice & heavy cream. Just heat the tomato juice & add a pinch of baking soda along with your seasonings of choice (salt & pepper - perhaps red or white pepper instead of black - maybe a splash of tabasco or worcestershire sauce). Be sure the pan is big enough to allow a little frothing up when you add the soda.
When the tomato mixture is simmering, add the cream & reheat to serving temperature - do not allow to boil.
Again, this isn't meant to taste like Campbell's - it's just the way my mom made tomato soup & I've adjusted it for lower carb by using cream instead of milk. Bon Appétit!