In my experience, cooking is more of a science than an art. That said, it is very much by feel. It is similar to Fourier transforms, once you have chugged through enough integrals you can just look at one and simply write down the answer. While I am speaking of math, once you have a recipe scaling it either up or down is usually simply a matter of math, you'll get the hang of it, just don't be afraid.
If you are just beginning to learn to cook, it is normal to not have things turn out just the way the recipe says, even if you "follow" the recipe exactly. For example, I love bread but for the longest time I could never get a loaf of bread to turn out just quite right. In the process of making of many inedible loaves, I learned a few things. All of a sudden, I got a loaf to turn out nearly perfect. Then another, then a loaf that didn't do so good, etc. Now, it seems that I can do nearly anything and get a loaf to turn out perfectly. You just seem to get a feel for things and it all works out.
To any readers, do not be afraid to fail nor experiment. I love experimenting in the kitchen. it is like a chemistry lab...kind of. I once had a recipe for baking powder biscuits. I wanted to know why it called for baking powder and not baking soda. So, I reduced the recipe to make enough for just one biscuit. I made a control just as the recipe stated. I tried the recipe once with baking soda, once without salt, once with oil in place of shortening, once with sugar, once with water in place of milk, and a couple other variations I can not recall. Not all of the biscuits turned out even close to edible but I learned how certain ingredients work and what they change in a mixture. Life is all about learning and if you can constantly be learning, life is fun. The kitchen is one place to keep learning. Then pass on that knowledge.