Metafilter has an excellent AskMefi about cooking secrets (previously). One of the cooler things to come out of the discussion was a link to a site, FoodPairing, that suggests foods to pair with each other, and replacements for ingredients. It seems like it would be an invaluable resource for deciding on how to build meals.
Anyway, snippets from the AskMefi (most of these were repeated multiple times, so I’m going to take that as an indicator of good advice):
One thing that really brightens flavor is not using just the juice of fresh lemons, limes, and oranges, but adding the zest too, grated with a microplane. The difference is powerful.
Professional chefs use a shocking amount of butter. That makes a difference.
Seriously, stock is the foundation of a huge swathe of world cuisines. It doesn’t add depth and richness and flavour, it is depth and richness and flavour.
I think eating at really good cheap restaurants and then trying to copy the food they make is a good start. I’ve been working on my fish tacos a lot lately, after having some amazing ones at a local place. I think mine have become just as good. It’s been fun trying to copy and then improve on their recipe.
don’t make pasta and sauce separately and then pour the sauce over a plate of pasta (unless you really want to for some reason). For better pasta, blended with its sauce, do this: Make your pan sauce and leave it in the pan, with enough room for adding pasta later. Cook the pasta in water, stopping it just a hair short of ‘done’. When you drain the pasta, save some of the water you’re draining from it, either in the cooking pot or in a basin under the colander. Add the pasta to the sauce pan, and also add a little bit of the retained water. Simmer the sauce with the pasta in it for a few minutes before finishing and serving.
And then other, more in-depth, responses.