First of all: ingredients
Paul Bocuse (if you don’t know who he is you should find out now!) once said: “French cuisine supremacy will last untill italian chefs will realize the huge heritage available to them, both for raw materials and for countless different culinary traditions available to them.”
Italy is a unique place. Not just for its history and arts, but also for its foods. Every region, every single town in Italy has its own traditions and the variety of geography (mountains, plains, hills, sea) offers hundreds and hundreds of different raw materials that can become excellent foods, great ingredients.
The raw materials are the foundations of a recipe. You could be the best chef in the world and try to cook the best recipe of the century, but if you use bad ingredients your result will always be poor. The first and most important thing about a good dish are the raw materials.
One should always try to get the best and most fresh ingredients available. Frozen ones can be good enough in some cases, but it would be much better to use fresh ones. Avoid if possible pre-cooked foods, processed ingredients that could be bought fresh or at least frozen. Check always its price (cheap ingredients usually are cheap for a reason) and its origin (if it says it’s italian food but it’s written made in china I would not buy it).
You do not want to build a house with cheap and unknown bricks. So you should never cook with the wrong ingredients. If you can’t find the right ones, just change recipe. Never settle for a compromise when you want to cook.