I was always drawing stuff, but naturally I mostly drew things I had an interest in. I loved cartoons, comic books, science fiction and monster movies so those are the kinds of things I drew as a kid. When I began taking art a little more seriously and thought I might make a go of it as a pro I started focusing on drawing people well. I began focusing on anatomy, proportion, likenesses, lighting, body language, foreshortening, etc--all at once. The Kubert School was a great help because we had life drawing class there. Drawing live models took me off the "comic book anatomy" path, and put me onto a path of drawing from life.
One of the best things that any artist can do is to get away from drawing only the things they enjoy, because the things you enjoy drawing are often fall under the category of comfort zone subject matter. Artists tend to already be pretty good at producing decent work within their comfort zones, but if you want to grow as an artist you have to start drawing things you're NOT comfortable with. Often those things involve things you don't have much interest in, or that you haven't much experience in drawing--at least not too often. For instance: if you're not good at drawing children, you need to draw children more often. If you suck at drawing horses, start learning to appreciate cowboy movies, and buy some books on horses. Start learning to draw past your weaknesses. If you want to be a well rounded artist, you can't cower from your weaknesses. You have to pin those down, and begin to transform your artistic shortcomings into artistic strengths. The only way to do that is through the experience ofdrawing and effort. Failure in artwork is often a very beneficial thing, providing you learn from how things went wrong. There's no shame in falling flat on your face in drawing if you walk away from the experience smarter and better prepared for next time. Failure is a great teacher. It can put you on the road to success, so don't be afraid of it.