Avoid the Powder
Garlic is the ultimate sauce enhancer. Whether used fresh, sautéed, crushed or chopped, garlic adds its own unique flavor interest. On the other hand, try to avoid garlic powder in this particular situation; it will add a bitter, heavy aftertaste to a sauce.
Another way to change the flavor of a sauce is to add chicken stock or chicken broth. This gives a tomato sauce a quick flavor fix. Add about ¼ cup of chicken stock or broth for each cup of tomato sauce. Use a little less than ¼ cup if using stock to enhance a white sauce. Beef stock is another option for a red sauce. Again, use about ¼ cup of beef broth to 1 cup of tomato sauce.
When using fresh herbs in a sauce, add them near the end of the cooking time. Putting them in too early will alter the taste since fresh herbs do not hold up as well in heat as dried herbs. Conversely, if you are using dried herbs in a sauce, put them in at the very beginning. Dried herbs need time (and heat) to rehydrate and round out their flavor. Generally, you will need to add three times as much fresh herb as dried herb in a recipe. For example, you would use 3 tablespoons of fresh basil in place of 1 tablespoon of dried basil.
Want to sweeten your tomato sauce? Sugar may be a good bet, but use with caution. While it can be used to cut the acidity of tomato sauce, it must be used sparingly because too much sugar will result in a “bottled” taste. Keep in mind that some of the best flavor in a tomato sauce comes from the natural acidity of the tomatoes, so don’t blot it all out.