A couple of weeks ago I got hired to work my first job! The process was definitely new to me, (which was evident as I didn't realize that *cue Chris Traeger voice* "literally" every single place wants you to fill out your application online) and I had absolutely no idea how to go about showing each establishment that I was serious about this job and, on the other hand, they would get a lot out of hiring me as well. Here is the short list of the things I've compiled that I learned to highlight about myself (from employees and managers alike) in order to prove myself as a worthy applicant.
1. Previous experience
Past experience may be a bit of a no brainer, but it can be a hard thing to check off on your list (especially when this is your first job that we're talking about). When updating your resume, be sure to include any activities or involvement that has something to do with the job's daily responsibilities. If customer service is a part of your desired job, including things like volunteering in your free time or even babysitting can help make you seem like a better fit.
If you're applying for a position within a company that generally requires experience (that you don't have), you might be placed at a lower level position with the potential and purpose of rising through the ranks. This was something that I experienced when applying to be a server at several different restaurants. Many establishments explained to me that they typically start people with no "true" serving experience as a hostess to learn how the restaurant functions with less responsibility dumped right on you.
My boss told me once that one of the main reasons he hired me was because I made him smile in less than a minute in our interview. I had no real relevant serving experience, but that's far from a make or break. You can be over-qualified, but if you aren't a team player or someone that won't provide a friendly atmosphere to anyone who walks through the door, say hello to the curb for me, because you're about to get kicked to it.
3. Passion (and maybe a little persistence)
It's okay if you don't know all of the ins and outs of how your job works. That's why training exists! The most important thing is that the person in charge of hiring can see how much you want this job and is able to assume you'll work just as hard to keep it.
While dropping in to many different restaurants in my area, I noticed a similar theme in every response on how to apply. Fill out the application, then call back in a few days. After asking one of the servers at Baker's Crust about when to call back, she told me that it was important to the hiring manager to see that you really, REALLY want this job (so like basically two days after you submit).
Some places will offer you a position on the spot. Some will keep you in their records until they have a spot open. A few weeks ago, I applied to about 10 places and I JUST heard back from one saying that they'd love to interview me. This being said, the sooner you get your applications in, the better.
No matter what job you're applying for, always remember the four Ps and: maximize previous experience, express yourself and your personality, shown your passion, and remember to be patient and know that eventually, it'll happen. Good luck, and go get 'em.