Seafood pasta is the signature dish of our household, with Linguine and White Clam Sauce inarguably holding the top spot. Still I am at heart, a lover of variety. That's why especially in summer when fresh fish most appeals to me, I like to change things up a bit and create different variations of shellfish over pasta, whether in white (oil/broth based) or red "tomato-based" sauces.
One thing is for sure, once you master the very forgiving technique of most basic seafood pastas, you are almost guaranteed a quick cooking meal that tastes and feels special. Just be sure you are choosing the absolute freshest fish you can find - it will make all the difference.
Below you'll find some of my rules and techniques for successful Seafood Pastas plus a few of our favorite recipes that you can try. Once you get the hang of them you owe it to yourself to improvise one on your own. You'll be surprised at how easy it is.
TIPS
1. Always clean, prep and chop non-fish ingredients ahead. Seafood pastas are quick cooking so if you aren't prepared, your timing can be really thrown off. Chop all vegetable or herb ingredients in advance (usually garlic, shallot or onion, and a green like Italian Parsley).
2. With shellfish, smaller is always better. Particularly with bivalves, the smallest Littleneck Clams or Mussels are the way to go. I always find them to be sweeter, fresher, and more flavorful. If you cannot personally select them just ask your fishmonger to select the smallest they can find. Shrimp is probably an exception to this rule, as the various sizes can all be delicious as long as they are fresh (and preferably, Wild & American). Consider your recipe in choosing the most ideal Shrimp size.
3. Scrub and prepare all shellfish as directed - this is crucial because no one likes a sandy dish of food. Additionally, the process of cleaning is your opportunity to to do some additional quality control. I personally sniff every Clam, Shrimp or Mussel that I serve. If anything has a cracked shell, or smells a bit off, definitely toss it. Your nose will almost always steer you in the right direction. The internet has a wealth of information on cleaning your shellfish, and you'll find tricks for all varieties (for instance, Ina Garten submerges Mussels in cold water with flour to get them to unleash any sand or impurities). Your fishmonger may also be able to execute timesaving measures such as peeling and deveining Shrimp. Even if you have to pay a little extra, it's nearly aways worth it.
4. Salt the pasta water. This is the rule almost always, but I find it particularly important with Seafood Pasta which is usually delicately flavored and layered.
5. Don't overcook the pasta. Please. Al dente is crucial, and to get it perfect ever time, I time it! Also, always reserve some pasta water to loosen the pasta if necessary or add to the sauce.
6. Don't overcook the Shellfish. Noticing a theme? Whether clams, mussels, here is my secret to success -- the second they open, take them out and set them aside in a bowl to catch the juices. To achieve this, you'll need to stand by your pot with tongs and work quickly, checking under the lid of the pot frequently. This is no big deal - Shellfish cooks so quickly and there's nothing worse than rubbery seafood (I'm talking to you, Calamari).
7. This one is more a suggestion but I can't resist -- skip the Cheese! There's an unwritten rule that Italians don't put grated cheese on Seafood. I abide by this rule and it has never failed me. If you follow these steps, the flavor will be there - or there is not much a sprinkle of Salt can't fix.
BASIC METHOD
1. Start your salted Pasta Water boiling.
2. Add either Olive Oil or Salted Butter to a large, deep pan. (I actually like a mix of both - depending on how many you are serving, either one or two Tablespoons of each will do. Warm it over a medium flame taking care not to let it smoke).
3. Add minced fresh Garlic or finely chopped Onion or Shallots. These are always good aromatic base ingredients. Cook gently taking care not to burn, especially if we're talking Garlic. If you burn the Garlic, dump it and start over.
4. Time for Liquid. For Clam Sauce I use Clam Juice and White Wine. White Wine, even in a red-based sauce, is preferably. It won't turn your Calamari or Onions purple. That's a plus. As an aside, if you are cooking Calamari, always cook the Tubes before the Tentacles, removing the Tubes before cooking the Tentacles, the reason being that the Tentacles have the purple pigment which will turn the whole dish purple - it'll taste fine but won't look as good.
5. Once your liquid is bubbling, add the shellfish -- Clams, Mussels, a mix, etc. If you are working with Calamari, Shrimp, or finned Fish, I usually choose to cook them in a separate pan and toss it all together towards the end b. If you are adding "red" or Tomato Ingredients (fresh chopped Tomatoes, Sauce, Paste, now would also be a good time to add it). Cover to steam, checking frequently. As Shellfish begin to open, pull them out one by one right away and place them in a bowl to catch the juices. Continue until all Shellfish has opened and discard any that take much longer than the rest.
6. Want it more brothy? You can always add more wine! Also add Salt, Pepper, Crushed Red Pepper as needed at any point in the process, just be gentle with Salt as Seafood has natural salinity. My rule of thumb: you can always add but never subtrace salt. If you over-salt, Lemon can some times counteract it. Speaking of Lemon, Lemon Juice and Zest are natural partners to "white" style Seafood Pasta preparations.
7. When are you done? Your fish and Shellfish is all cooked, you have some sort of brothy sauce or tomato based sauce, and your Pasta is done and drained (with some pasta water reserved). Either plate the Pasta and top with Shellfish and Broth, or toss it all together in a large, high-sided pan. You can add a few drizzles of Oil and/or some Pasta Water to create more of a sauce (stirring consistently). Taste for Salt, Pepper and add fresh Herbs to finish-- my favorite is finely chopped Italian Parsley for versatility. Serve and enjoy!
Some Recipes to Get You Started
Scallops With Sungold Tomato Pasta
Linguine With White Clam Sauce
Spaghetti Rigati With Lemony Calamari
Rainy, gloomy, and damp, today is just a Chicken Soup kind of fall day. 
