I've been making my own spaghetti sauce since my hubby and I were married in 1990... and although I've made it for years... I don't think I've made it exactly the same twice. Part of the reason... is that each time, I try to use local veggies... and that varies from year to year.
And... with weather and location changes (we've lived all over the USA)... the taste of those veggies can be vastly different.
After all, tomatoes grown in the dry sandy soil of New Mexico, do in fact, taste different that tomatoes grown here in PA.

The important things about making spaghetti sauce though (at least for me)... is get good produce.
This year I was gifted a box of tomatoes from a friend... they looked like romas. They were not the best looking tomatoes in the world... spots, soft areas... but sometimes these "seconds" veggies taste the best... and they are absolutely perfect for sauces and soups.
And so... I chopped up all those tomatoes, and combined them with a few heirloom tomatoes I had gotten at the farmer's market on Friday... and put them in my biggest pot with a couple cups of water (I need a bigger pot). Use the biggest pot you have. You won't regret it.

While they started to cook down, I chopped up some other fabulous finds from the Potter County Farmer's Market. I chopped up sweet red peppers, green peppers, fresh garlic, scallions, a couple green zucchinis and a couple yellow squash. I chopped them in good size chunks, because I was going for a more chunky, rustic style of sauce.

It took about 20 minutes or so for the tomatoes to cook down a bit... and then I added in all the chopped peppers, scallions, squash and garlic. I also added in some fresh basil, chives and parsley from my herb pots.... and some dried oregano I had on hand, a couple of bay leaves, salt and pepper.

So ... here's where it gets interesting. I know there's a lot of controversy with spaghetti sauce.
What kinds of tomatoes... to leave the skin on them or not.... to de-seed them or not....
to put them through a food mill... or a blender... but here's the thing.
It's doesn't matter. It's all good. Whatever you choose to do is fine.
(and for the record, I leave the skins on, I don't de-seed, and a few times I've used a blender, but most of the time I just let it cook and mash it on occasion with my spoon).

When I was a kid, my husband's family had spaghetti every Wednesday for supper. When I worked with his mom at the hospital, I would often join her on spaghetti nights for dinner and a chat. It was tradition (and locally known) how she made spaghetti for "Mama Russell's Home for Wayward Boys"... and later for her grandkids, neighbor kids... and the like. It was; and still is, steeped in tradition.
When Jim and I were "getting serious"... I had the talk with "mama Russell" or JEEP as she was known to everyone... not about sex.
But about her sauce. It was a closely guarded secret. And yes, I know it. And I will tell you one "key" trick. Let it simmer. OVERNIGHT. You heard me. Make most of this before you are ready to go to bed, then let it simmer on the stove all night with the lid mostly/ but not completely on. This allows it to slowly cook and develop those flavors, and lets it condense a bit so it's not a "runny" sauce.

In the morning .... give it a good stir, taste it... and add some more spices if you want.
Jeep would be proud.