I've let it cook down - simmer - until it is very thick and it helps to add some sun-dried tomatoes to it cut up into slivers. They richen the sauce as well. If you want to cool it for freezing or keep in the fridge for some time it helps to let it cool without a tight cover on it.
Cooking is like love, it should be entered into with abandon or not at all. Oregon native transplanted to Chicago....