Design school was a great. After a couple of years of working as a flash designer and now running a design studio, I've learned a lot - some the hard way, some not... some I was lucky enough to learn while I was still in school, most I had to learn afterwards.
1. Your degree won't get you the job
Your portfolio will. When interviewing for a design job, a future employer will be much more interested in seeing what you can do. A design education is definitely important - it will teach you design processes and technical skills that you will need. But a great portfolio will be your foot in the door.
As a side note, keep in mind what position you are applying for. For example, if you're applying for a web design position, make sure that you have a great online portfolio with examples of websites that you've designed.
2. Prep yourself for the career you want
Along the same lines as #1, sometimes a design school education is very broad. I received my degree in industrial design - now I work in web design.
I discovered what I was interested in while I was still in school, I got a job during school that prepared me to enter the web/interactive design world. I learned skills that I needed to get my first job at a flash agency. But I credit that first job that I got during school with my successes in my current position.
When still in school, figure out what industry you want to pursue. Whether that be automotive design, packaging design, interactive design... and focus your work and your portfolio there.
3. It's who you know, not what you know
While you're in school, go to industry networking events whenever you can. It's important to start meeting people who are working in the industry that you want to go into. Even with an impressive portfolio, making a personal connection with someone is even more important - and will up your chances of getting that interview.
Even if industry events aren't really your thing - get out and meet people. Sports leagues, volunteer organizations, etc are great places to connect with people. You never know who you might meet. While networking with people, don't constantly try to sell yourself - make a personal connection with the person.
4. The real world moves at a faster pace
Your clients will work on their own time, and that's typically ASAP. The key to success in the design world (esp. graphic and web) is speed. Learn the shortcuts and key commands in whatever design software you're using.
Although we know good design takes time, the real world doesn't give you that time.
5. The majority of the work you'll do will not be the fun stuff
In design school all work was the fun stuff. You got to be as creative as possible. You got all of the creative control. That's not the case when you start your first job, that's not the case even when you become the head of a design studio.
At your first job, there will likely be busy work, doing the parts of projects that lead designers don't do, because they're spending time on the fun stuff. When you head up a design studio, there's the paperwork, drafting proposals and estimates, negotiating with clients, collecting payments, networking events, etc.
6. Backup your work
Not only because your computer could crash. Whenever you're working on a project and are about to make a drastic (or not so drastic) change to your work - "save as" - create another version of your project. If something goes wrong and you need to go back, it's much easier to open up a previous version than to hit the Undo button 30 times.
7. The learning process never ends
Just because you graduated from design school, doesn't mean that your design education is complete. You must keep up with design trends, industry news and software updates, etc. Otherwise, you'll be left behind.
