Job searching can be so frustrating. Fortunately I haven't had to do it in a while, but I do conduct interviews.
I agree with Crankin that you should always look good, even if you are just picking up an application. That doesn't mean you should wear a suit, but unless you are applying to a bike shop, don't wear a jersey. I also agree to check with the job placement offices at school. Also let your professors know that you are searching. When we open a new candidate search, the first person I call is my graduate advisor.
Think about the challenges you faced in the temp jobs or volunteering. Did you have to work with a lot of people and personalities? Handle high-pressure situations? Learn new skills quickly? Operate on a shoestring budget? Organize other volunteers? Parley these into skills on your resume.
When they ask if you know how to make coffee or fix a bike, don't tell them what you don't know; tell them what you do know. "I do small repairs on my bike, but have limited tools... I am very mechanical and learn quickly... I help my friends do simple repairs on their bikes..."
Also, when you apply on-line, notice the key words in the ad and tailor your resume to include those words. Whether it is scanned by a computer or a person, those words will be picked up on. Just don't turn your resume into a stream of jargon. And do NOT use the same resume for every job.
Good luck.
I stand and rejoice every time I see a woman ride by on a wheel...the picture of free, untrammelled womanhood--Susan B. Anthony