Get the mixture of the sauce all in a pot...if you use fresh ingredients to whatever extent it will take longer to cook...if you use ready made it will only require heating.
If you are using fresh tomatoes after cutting them up cook them first with some water and spices. After they are cooked down add the other ingredients and cook everything until palatably soft. At most after addition it takes only about four hours to cook after the tomatoes are about right (unless one is doing a slow crock pot cooking. In a crock pot it is usually advisable to not add too much spice as spices are liberated more with longer cooking...remember this when reheating your spaghetti). The tomatoes make take a day or two to cook down.
Bring the sauce to a slow boil and bring the temperature down to where is is just barely simmering and cover the pot...cook until everything is soft enough to be palatable.
After the sauce is done bring a pot of salted water to a rolling boil. Add the type of pasta you prefer in the amount you like. If you prefer the spaghetti smaller in length break it up first before cooking it...
To tell if the spaghetti noodles or pasta is well done there are two ways to check it. You can throw it against a smooth surface and see if it sticks. People do not count it has to be something like a linoleum wall....or tiled wall - Or bite into the pasta to see if it is soft all the way through (be careful to let it cool first).
Before draining the pasta add your favorite type of oil to the water and mix. This will help keep the noodles seperated...if you do not have any oil butter or margarine will usually suffice....
And if you are doing this to impress someone always have the number for take out in case your meal does not turn out. Also if it is important make your spaghetti at least once before trying it out on anyone keep track of what you do to be successful...
Spaghetti can be just about anything added or deleted from it. The best spaghetti usually takes the longest and uses high quality ingredients and meats. One can substitute even seafood for the meat if they prefer but a different set of spices usually work better for seafood (also then you are getting more into linguini).