When my husband was hospitalized with a bone infection, we stayed at the Fisher House in Landstuhl, Germany to be closer to him. One of the other guests was from Italy. One night she showed me how to make a delicious spaghetti sauce that didn't taste like it came out of the jar.
Saute minced garlic and a finely chopped onion until the onion is transparent. Lower the heat and splash in some red cooking wine. I just cover the bottom of the frying pan and let it cook for a few minutes, but I don't let the cooking wine boil dry...just simmer. Then add the jarred or canned spaghetti sauce. Turn up the heat and let it start to bubble. Pour over your cooked pasta and sprinkle with shredded or grated Parmesan-Romano cheese. This is the hard block of cheese, not the stuff in the green can. It's more expensive but it tastes much better. My neighbor just visited Italy and brought me home a block of Parmesan cheese that has matured. She says it's even better than what we can buy at the grocery store. I can't wait to try it.
Other variations:
Add ground Italian sausage to your sauce. Or chop up canned palm, canned artichokes, and/or fresh red pepper. It's really yummy and the kids like it, too.