Heyoooo 2014 MSE grad here. Unfortunately I got snubbed by internships two summers in a row (got to the last round of interviews and then didn't get it), so I did a variety of things to get relevant experience. At one point my composites prof (was Dr. Bin Li at the time) offered up some undergraduate research and I jumped on that. You can go around to various professors and see if they need help on any of their projects, I'd recommend that. If you're interested in a particular material type, go to the professor that specializes in that (Dr. Field for metals/nanofibers, Drs. Bandyopadhyay for biomaterials, Dr. Zhang for composites/nanocomposites) and hound them until you get in with them. Some have requirements for GPA or being good students and whatnot, so you might have to work for it.
It took a while to find an open position that I was qualified for after graduation, and when I did it was a Flammability Technician with an aerospace company in Seattle, not at all what I was planning on doing with my degree. Ended up being there about 8 months, then was unemployed for a while, now I work as a Quality Engineer at Exotic Metals Forming Company in Kent. My experience as a flam tech was critical in getting this job, and I'd recommend getting anything you can in the field that you're looking to go into. Don't be discouraged if all you can get is a manufacturing worker or low level technician at first, getting in the workforce is the most important aspect. I know you put in all the time and work to get your degree and you're ready to just get out there and get paid for it, but it can take some time.
Work experience is key, but I would be remiss if I said my experience as an ultimate frisbee player and captain at WSU was worthless in my interviews. Extracurriculars that you care about are also important in showing employers that you're a human being with your own interests and passions, even if it isn't doing [insert whatever that company does]. At the end of the day, these people are going to have to spend at least 40 hours a week with you and they want to know you're not going to drive them crazy.
All this was my personal experience, and I was admittedly a bit of a slacker when it came to job fairs and job hunting when I was still in college. Put in the work on that side of graduating and you're probably going to be better off than I was. Then again, I got to go on a 50 day trip to SE Asia because I didn't have a career job yet, so it came with highs and lows. I'd recommend travelling before locking yourself down after graduation.
Hope that helped! Go Cougs!