My first contribution to the corporate design community is to advise you to diversify your skills. When I graduated from college, I went through all the normal theory classes, and decided to specialize in web design because that was the big up and coming thing at the time. I have continued to expand that knowledge, but I never forsook my print design base. Not only did I educate myself on blogging, search optimization, pay-per-click advertising and email marketing, but I also eagerly took on work that involved billboards, screen printing design, vinyl vehicle wraps, anything a little less common to normal print layout.
Get Out of Your Comfort ZoneWhen you diversify your skills it adds value to yourself in the minds of your employers. Boss' don't like to take risks, they want someone that has experience when they assign projects. If you're the only designer with experience in vinyl design and the boss has been envisioning some nice vehicle wraps for the company cars. You then become more valuable in their mind than the other designers.
Bonus Tip:Sometimes taking on freelance jobs for friends can be for the experience rather than money. Continuing the illustration above, if you had no experience working with vinyl but a friend needed it but didn't have any money, gaining that experience could be more valuable than the actual income earned from the project. In your corporate job next time the boss has a need for vinyl, you can chime in with "I have experience with that!" Brownie points! Leave out the fact you just did it last week, and it was a freelance job on the side, for some reason boss' aren't too keen on you thinking about anything other than "The Company".