If you've spent much time in the kitchen, you probably know that while cooking is an art, baking tends to be more of a science. A number of chemical reactions take place inside the oven and, with the wrong proportions or a little deviation in cooking time, you can wind up with rather liquid pies and deflated soufflés.
Making wine is no different. It's very important to stick to the directions supplied in your winemaking kit or recipe, especially if you're a beginner. A quick Internet search will yield a long list of ingredients that home winemakers can add to tweak their wine: enzymes, nutrients and a host of chemicals. However, throwing everything in won't guarantee better results. In fact, too much uninformed tinkering is a great way to produce a thoroughly undrinkable vintage.
As with most endeavors, there will be time enough for innovation later on once you have the basics down. In addition, the more you do to your wine, the better it is that you understand the science behind what you're doing. As the old saying goes, you have to learn how to crawl before you learn how to walk.