Hard cheeses can be stirred into pastas but are most often sprinkled on top at the last minute, adding a final blast of flavor. Many varieties are aged, giving them a bold, salty taste, so a little goes a long way. For maximum freshness, buy hard cheese in wedges and grate as needed. But pre-grated cheese is fine, too. Bring it to the table and let people serve themselves.
Soft cheeses make sauces wonderfully creamy and rich. And because they melt quickly, you can incorporate them easily into pestos, marinaras, and puttanescas to give plain noodles a smooth, flavorful coating. Crumble or chop the cheese before adding it to a dish, a couple of tablespoons at a time, tasting as you go.