Perfectly cooked pasta is called "al dente," which in Italian means "to the tooth." Al dente pasta is cooked just enough to retain a firm texture while being fully pliable.
Boil the pasta according to the package's instructions.
At the minimum cooking time indicated on the package, or even a minute before, remove a piece of pasta from the boiling water with a fork.
When it has cooled enough to touch, taste it.
If the pasta is mildly chewy but doesn't stick in your teeth, it is done.
If the pasta seems a little hard or sticks to your teeth, cook it 1 minute longer and test it again.
Avoid overcooking your pasta.
If you don't relish tasting hot pasta, cut a piece in half. Then look at the cross-section of the pasta. If you can see a difference between the very center and the outer ring of the pasta, it's not done. If the pasta is one continuous shade and texture, it's done.
Remove the pasta the moment you discover it to be "al dente" and eat it immediately.
Italians never rinse their pasta.
That "flinging the pasta against the wall" method might be fun, but it's not so reliable. Overdone pasta sticks, too.