Adding Spices, Herbs, Salt, Etc...
First of all the best way to enhance the flavor of your pizza is to use Fresh Herbs vs Dried. The difference between Fresh and Dried is that Herbs are the leaves and soft stems from a plant and spices are the dried seeds, roots, or bark. You can get Spices whole or ground and whole spices stay fresher longer. Ground spices are usually more handy for everyday cooking. If you are going to substitute Fresh for Dry, a rule of thumb is to use half as many, you can always add more.
Keep in mind that dried herbs need time to cook for the flavors to come out, you need to activate the oils with either friction or heat. Always buy the BEST YOU CAN, please don't buy the spices you see for .99 cents!!
When making pizza Basil and Oregano are two of the most popular spices used followed by garlic powder, onion flakes, thyme, black pepper and salt. Salt is actually a mineral, not a spice. Therefore, it does not lose its flavor over time like spices and herbs do. Salt has been an important player in world commerce and cuisine since ancient times, and "salts" our language and literature as well. No kitchen is complete without salt. (Source: The SpiceHouse)
Salt will reduce bitterness and enhance the other flavors and ingredients in your recipe.
When tasting your food, ask yourself if the dish is bright and are the flavors working together rather than just solely concentrating on the level of salt.
I'm a fan of the product Accent, a lot of people don't like it because of the MSG stigma. Accent Flavor Enhancer food seasoning has no artificial flavors. As their product info says - "We are all about providing easy cooking solutions and helping you wake up the flavors of your food. Accent adds depth to food flavor. It’s been a ͞secret ingredient͟ of many chefs for years. Accent has 60% less sodium than salt (salt contains 194mg sodium per 0.5g) and is a terrific salt alternative for people watching their sodium intake" Umami is considered the fifth basic taste in addition to salty, sweet, sour and bitter.
If you would like to make your own Italian Seasoning Blend, here is a recipe that I use.
1 1/2 Tbsp Oregano, 1 1/4 Tbsp dried basil, 1 Tsp Rosemary, 1 Tbsp Onion Flakes, 1/4 Tsp Dried Thyme, 1/2 Tsp Sea Salt, 1/2 Tsp Red Pepper Flakes, and 1/2 Tsp Garlic Powder.
Another ingredient I use as a 'Seasoning' is Mike's Hot Honey, if you have not tried it I highly recommend it! Finally, another option for adding a seasoned flavor to your pizza is to flavor the outer crust with a Garlic Butter mixture or even Mike's Hot Honey.