Making Tomato Sauce from Tomato Paste I've been trying, on-and-off when I have time, to make tomato sauce from a 5 1/2 oz can of tomato paste, but haven't figured out the right proportions of ingredients.

I've been combining a can of tomato paste with about 16 oz of water and some sugar to cut the acidity, and reducing it a little, but all I end up with is watery tomato paste.

It's more likely that I am missing a key ingredient (like a can of diced tomatoes) than a critical preparation step, but I'm curious about other people's experience.

Edit

By "tomato sauce", I mean something functionally equivalent to a store-bought jar of pasta sauce. 

Why would anyone want to do this? I honestly have no good reason. It is mere curiosity on my part. Is it possible to get edible results? Or is it guaranteed to be a complete waste of time, not worth even experimenting with?
I can give you the Italian answer - first of all, normally we don't use tomato paste to make sauce, but rather to add a tomato "kick" to recipes. Tomato paste is simply tomato puree that has been cooked down to a high degree of concentration. 

A basic tomato sauce is made by 


making a soffritto with onion, carrot and celery (plus other flavors)
adding tomato puree, or "pelati", more rarely fresh tomato
cooking the sauce down until the taste and thickness is what you want


If you want to use paste instead of puree, the third step has to be omitted or greatly reduced in duration. Keep in mind that tomato paste has its own taste, and that taste will remain in the final sauce.