This one's easy!
Take 2 large (15 oz.) cans of tomato sauce and heat in a large saucepan. Add whatever excites you - spinach, herbs from your garden (or your spice rack), garlic, onion, vegetables, meat.
Some herbs that are nice with this:
Rosemary (my fave!)
Or you can experiment with smaller batches and try:
Allow the sauce to simmer at least half an hour - the longer the better. I then pack it in my Ball Freezer containers (available at the grocery store by the canning stuff) and freeze them. Thaw one or two prior to dinner. One is perfect for two people, two is just right for 4.
And no more wasted sauce because you didn't eat the whole jar.