@Greedytiger I don't really follow recipes, I just make it up as I go along.
My basic tomato sauce goes a bit like this:
Fry diced onion, grated carrot, diced celery with salt & garlic paste and a splash of water with the lid on the pan so it softens. You can add whatever other veg you've got in as well, peppers or mushrooms are good.
Add a tin of chopped tomatoes (or 2, depending on how many people you're feeding), salt, garlic powder and whatever herbs and spices you like. Chilli and paprika works well with meatballs I find.
Simmer down until the sauce is thickened.
I change up the seasoning all the time. Whole grain mustard, pesto, worcestershire sauce and Marmite all can add a certain "je ne sais quoi" to a dish that really lifts it, depending on what you've got in there.