How can you be a great cook
Use great ingredients. Not too many of them. Treat them simply. Remember to season with salt. And always make enough for seconds. Let us know if you'd like any recipes -- we have lots of good ones.
It's like so many, if not like most, things---one just has an intuitive feel for whatever it is and good training is what one needs---or one doesn't have it and good training/education really helps immeasurably, but will not make one outstanding in the field. You can't "train" an excellent psychotherapist, you can't "train" a great cook, you can't "train" a great artist, you can't "train" a great mathametician, etc....
Me again--to become a good cook, do what Amanda says and read lots of recipes for lots of things as you cook and you will develop a feel for what appeals to you, would work, etc. Read, read, read, and cook, cook, cook.
And be careful with the salt as they say it's not so good for us, as great as it tastes!
also, spend time in the kitchen with more experienced cooks! taste new foods. and cook! the more you do, the more comfort you will gain in the kitchen.
I'd say it's about practice. Getting to know when somthing is done just right. There are lots of little tricks that you can learn from experienced cooks and books and discussion boards. Use tested recipes from trusted sources, so you don't get discouraged by ones that don't work. But I like what Amanda said and starting off making simple, quality dishes is a great launching board.
Love cooking, love your ingredients, go slowly, read cookbooks, cook with people you consider to be great chefs/cooks/bakers, cook all the time and share your dishes with people and ask for feedback. Going back to love - if you don't love it don't do it.
And ask questions all the time about everything.
Eat -- pay attention to what you eat, train yourself to appreciate the true taste of food. This may mean less salt, less sugar -- in moderation they enhance taste, in excess they mask it. Buy food that is fresh and seasonal, since that's when it tastes best.
Read -- cookbooks, yes, but learn about the food itself. Follow the food 52 conversations on FoodPickle -- there's a lot of knowledge and range of opinion here.
SKK is so right: the essential ingredient is love. After that, or perhaps alongside it, Amanda's advice is golden: use good ingredients, do just enough to them to bring out their intrinsic qualities, then get out of the way and stop. And as nutcakes advises, practice! And don't be afraid to toss something that just didn't work. I did that just last week with macaroni and cheese with bacon. I thought I had done it just right, but it was flat. I didn't love it, or maybe there was too much thought and not enough love in it, so out it went. It's all a science experiment!
To quote Ms. Frizzle from the Magic School Bus (a PBS show about science), "Take chances, make mistakes, get messy!" When entertaining, I mostly cook things I've made before, but there are a lot of hit and misses in between. Sometimes I'll eat out and love something, then try to replicate it at home - thank goodness for websites like food52, epicurious, etc. for references. I love to read about cooking; I counted the average number of books per shelf in the cookbook section at my local library and estimated over 1,000 cookbooks! Learn to cook your favorite foods well, so you always have a few great dishes in your repertoire.
P. S. People in my cooking classes ask me all the time (no exaggeration) what seasonings and spices I use. Salt and pepper. Of course we all need to consume less salt, but we all also need to consume less fast and/or processed food. If you're not getting your salt mgs from the latter, get some good sea or kosher salt and have fun! Take chances, as Sadassa_Ulna says, and don't be too constipated about the process or the outcome.
"Food, like a horse, senses fear."
That's one of my favorite quotes (I think it's Julia Child but I'm not sure) and it really freed me up in the kitchen to just try things. If it doesn't taste good, you learn from the mistake and you get better.
There's a widely cited concept (might be apocryphal) that to be expert at something, you need to put in 10,000 hours of practice at it. Since there are an average of 2080 work hours in a year, that means about 5 years of full-time practice. So, start cooking and experimenting. You might not be great in 5 years, but you'll probably be a lot better than you are now.
When people ask me how they can become a better cook with out going to culinary school, my answer is always: "get the latest edition of the textbook from the Culinary Institute of America". It's called "The Professional Chef" and if you read it from cover to cover I guarantee you will become a great cook. I also think you should pick up the Websters new world dictionary of Culinary Arts to help you decipher the book if you run into anything your not familiar with. Good Luck!