Most marinades in this book follow a simple pattern:
Salt + Fat + Flavor + Time
Then, depending on the food, acid may be added for brightness, sweetness for balance and browning, heat for spice, and umami for depth.
Salt
Salt can come from kosher salt, sea salt, soy sauce, tamari, Worcestershire sauce, fish sauce, miso, anchovy, or seasoned salt. Salt should not be treated as an afterthought. If a marinade contains no salt or salty ingredient, it often tastes weak.
Fat
Fat can come from butter, extra virgin olive oil, avocado oil, animal fat, cream, yogurt, or sesame oil in small amounts. Butter is the flavor winner in many recipes. Extra virgin olive oil is excellent for marinades and finishing. Avocado oil is useful when a more neutral or higher-heat oil is needed. Sesame oil is powerful and should usually be used like a seasoning, not as the main fat.
Flavor
Flavor can come from garlic, onion, lemon zest, lime zest, dill, parsley, rosemary, thyme, paprika, black pepper, mustard, ginger, chili, miso, capers, vinegar, smoke, and fermented ingredients.
Time
Time is an ingredient. But more time is not always better.
Fish and shrimp usually need minutes, not hours. Chicken thighs can handle longer. Beef and pork depend on the cut. Acidic marinades should be watched carefully. Dairy marinades are often more forgiving. Enzyme-heavy marinades using pineapple, papaya, kiwi, or ginger can become destructive if used carelessly.
The best marinade is not the one with the most ingredients. The best marinade is the one that understands the food.