So, you are still in school and you want to be more than just another average employee someday? Here are a few things that can really affect your career in a negative way before it even starts!
Over confidence: Thinking that you know all you need to know and ignoring advice from people with actual job experience will cost you. Sure you want your independence and you are tired of being told what to do all the time, but being open to advice from experienced professionals will give you a serious boost in your career persuits. I wish I had started asking for advice (or reading career blogs) while I was still studying, I would have made much better career decisions in my early career.
Following the crowd: When choosing your career path or qualification, it's so easy to just do what everyone else is doing. Instead of doing some research and exploring your strengths, odds are you might want to follow your friends in their career dreams. Big no-no! Remember that you will be spending the majority of your life in the career path you choose, so make time to see guidance counsellors or visiting career fairs.
Waiting until it's too late: The earlier you can start asking questions about career choices the better. Even if you're still in school, ask your parents and their friends about their careers. Find out why they like their jobs (or not), and what an average day looks like for them. While studying it's also wise to try out some part-time jobs or job shadowing to give you a head-start. Stepping into your first full-time job with some experience behind you will definitely distinguish you from your inexperienced peers.
Rushing into things: Some of us really don't know very early in life what we want to do for the next 40 years. I was pretty clueless about which career path to choose because I have so many different interests. If you feel like this and it's at all possible, consider taking a gap-year to try different jobs or travel the world. Just because others know from age 5 what they want to do with their lives doesn't mean everyone else should.
For some more tips check out these posts: what I wish I knew before starting my first job AND what I wish I knew before entering the workforce.