By Laura Morsch, CareerBuilder.com

As a kid, you aspired to be a doctor, astronaut or princess. But as you get older, the innocent "What do you want to be when you grow up?" really starts to hit home. "I'm 20 years old," you may want to say. "How am I supposed to know?"

Whether you're just entering college or preparing for graduation, now's the time to start thinking about your career. While no single article can tell you how to choose your occupational destiny, Donald Asher outlines some common career planning mistakes to avoid in his book How to Get Any Job with Any Major (Ten Speed Press).

1. Confusing what you're good at with what you like to do.
You don't have to spend your life singing at weddings just because you have a silky voice. Nor do you have to become a chef because you have an uncanny gift with spices. To jump-start your career search, jot down two lists: one listing what you're good at, and one of things you love to do.

Though it might require more soul searching, the list of what you enjoy is the most important. Why? Because if you enjoy doing something, you'll do it for more than just a regular paycheck. You'll do it more often, you'll invest in training, you'll do it when it's difficult - you'll do it until you're good at it, and then some!

2. Confusing avocations with vocations.
So you've made your lists and discovered you love running, law, reading and basket weaving. Now you've scratching your head, puzzling over how to combine all of these aspects into one job. Don't worry - you don't have to.

Believing your job has to satisfy the whole you is a common source of career error. Mind you, this does not mean you can't love your job - you can just have a whole heap of activities and hobbies (avocations) on top of it.

For example, you may love to dance but you know you can't earn enough dancing as a career. Dance, then, is a great avocation for you. You can continue to dance for fun, but separately from your day job.

3. Confusing one aspect of a job with the whole job.
What you like to do doesn't have to the primary thing you do. Often people over-identify with the thing they like to do - believing they must become it instead of doing it.

A common example is someone who likes to write. Instead of looking for opportunities to do writing, he thinks he has to become a writer. He only pursues writing-only careers like novelist, journalist or copyrighter, when instead, he could have looked into being a minister, public relations assistant, editor or government lobbyist.

A final note: think creatively when considering which jobs to pursue after graduation. Your options are more varied than you might think