Hands down the most common mistake people make when cooking pasta is failing to salt their water properly. A teaspoon or two per gallon is about the maximum for most cooks. Yet that’s not nearly enough. As a good Italian friend of mine is fond of saying: it must taste like the sea! And that means a quarter cup or more of salt for that big dutch oven of yours. Just keep adding, stirring and tasting until you’re suddenly reminded of being a child — and the first time you dove headlong into the ocean surf. Holy cow, this really IS salt water! They weren’t kidding!
Adding lots of salt to the pot seems excessive until you remember that only a small fraction of the salt you’re putting into the water is actually going to make it into your pasta (though it’ll be the perfect amount to season it). The vast majority is going to stay in the water, and then get poured down the drain. But hey, this ain’t the Middle Ages. Salt is cheap and abundant. Live a little.