When I'm faced with an overload of qualified candidates, here are some of the things that can make me "fall in love" with one candidate in particular:
Do what you say you're going to do by the time you say you're going to do it. For instance, if you tell me you're going to send me a writing sample by Monday, send me a writing sample by Monday (or update me accordingly). If you send it Tuesday without explanation, I'll notice. It will even end up as a note on your application.
Be responsive. I pay attention to how quickly a candidate responds to requests for writing samples and references, and even how fast he or she returns phone calls. My assumption is that you're on your best behavior during the hiring process -- so if I have to wait days for you to get back to me, what will you be like when you're working here?
Ensure every communication is flawless. That means no typos, and no sentences written entirely in lower-case, even in your briefest E-mails.
Don't play it cool. Let me know you're excited about the job, if you really are. It's human nature -- people respond when they feel a personalized interest from you. Works in dating, works in job-hunting.
Ask good questions. Asking the right questions shows a level of thoughtfulness and engagement that a hiring manager loves to see. You can get some ideas of things you might want to ask about here ... and some more here.
Make it easy for me to check your references. Give me a neatly organized list of your references, with up-to-date phone numbers and a note about what your connection is to each, and make sure they know to expect my call. When a candidate gives me a list of references with outdated phone numbers and people who are hard to reach, I wonder if it's going to be reflective of other work they'll give me.
Be likable. Be friendly and genuinely interested in the people you’re speaking with, and show your personality. Be someone we'll start to want to work with.
Alison Green is the author of Managing to Change the World: The Nonprofit Leader's Guide to Getting Results. She is chief of staff for the Marijuana Policy Project, a nonprofit lobbying organization, where she oversees day-to-day management of the staff as well as hiring, firing, and staff development. Her writings have been published in the Washington Post, the New York Times, Maxim, and dozens of other newspapers. She blogs at Ask a Manager.