So I've been meaning to make this post as well. I was cleaning my room when I got back to my parents' house and I found this list of advice made by Adam Hughes back when I chatted to him about schools and preparation for the real world. If you don't know his work, he's an amazing professional illustrator in the comics industry and a link to his work is: http://www.justsayah.com/ . Anyways, here is some advice from him:
1.Always be humble, but never let anyone walk over you.
2. Always be drawing. You will be a better artist by the time you get to your 10,000 much more than you are when you finish drawing number 500. The sooner you get to drawing 10,000 (or 100,000 or a million), the better you will be. Draw ALL THE TIME.
3. Be a little fearless. You will make mistakes, you will miss deadlines, and you will produce bad art through no fault of your own. It's not fatal. I've screwed up just as many times as I've succeeded and I'm going on 22 years as a professional illustrator. Bernie Wrightson just had his 40th anniversary in the biz! Al Hirschfield died at age 100 and was a working illustrator until the very end of his days.
4. Keep your portfolio brief and fantastic. If you cannot win an editor's eye with 7 pieces of your best art, you won't do it by number 100.
5. If you're a girl, be mindful of your junk. Some guys will give you work just so they can get in your pants. It doesn't happen often, but it does happen. Be careful out there.
6. Experiment when you can, but focus as much as you can. Be great at one thing before trying to be the mistress of all trades.
7. Finally- keep your eye on the doughnut and not the hole. When you understand these words, you may leave the temple, grasshopper.
Thank you Adam for this great advice! I hope this helps anyone reading this!:)