I've spent the last two years on the graduate program admissions committee at the University of Illinois. Before that, I was the Director of Graduate Studies at the University of Georgia and served on their admissions committee any number of times. I'm wheezing across the finish line of this year's process. Here's some advice on good apps--if you'd like, feel free to spread far and wide. But always remember and repost that these are solely the opinions of the Oratorical Animal (John Murphy) and do not claim to represent the University of Illinois, the Department of Communication, or any of my faculty colleagues.
1) Complete your application fully. Complete it on time. I shouldn't have to say this, but students repeatedly forget to include some part or another of the application, the writing sample being the most usual suspect. In addition, our site, for instance, shuts down after the deadline passes. So, unless you want to make a lovely name for yourself with our graduate coordinator and staff by bothering them to apply after the date, check early in the fall semester on deadlines. Make a list of what you need to include. Complete the application fully and on time.
2) GRE scores matter. They are one of the rare data points we can compare across students, institutions, and nations. So, yes, they matter, but for those of you who do not do well on standardized tests, they are not the only thing that matters. So, several points. First, study for the damn thing. It's annoying, but it's worth the effort. Second, complete it on time (time--noticing a theme here?). Third, if you do not do well, if your score consists of 3 digits, for example, rather than the customary 4, then someone needs to address that issue. You need to say something in your personal statement or one of your letter writers needs to say something. Simply ignoring it as if it did not happen will not do. We'll notice if you're in the bottom 2% of all those who took the test. So, you need to say something.
3) Your recommendations should show that these people know you. I am not sure how this happens--I suspect that some students occasionally ask the most important person that they know. But those letters are usually terrible--1 paragraph, vague, useless. Make sure that those who write for you are happy to do so and are willing to devote some effort to the task. If they seem doubtful or tired, don't try to persuade them--the letter won't turn out well. And, as an aside, if you agree to write a letter for someone, don't be an ass. Write a real letter.
4) Your personal statement is not a memoir. It is not an audition for Oprah. Illinois is an academic institution. It values the life of the mind. This will be true of nearly every place you apply. This is graduate school. The emotional crap you're taught to write for undergraduate admission matters very little to us. As a matter of fact, we generally want smart students who are NOT constantly creating drama. So, if there is a narrative that opens the statement, it should be professional and clear. The statement should also have a clear focus--what are you interested in? What would you like to do? No, we don't care if you are a people person. Yes, we like the fact that you're obsessed with the impact that new media can have on public health campaigns. Tell us what you would like to think about. That's what we do--think. Finally, tell us how we can help you think. What is it about the University of Illinois--or Georgia or Penn State or whatever--that caused you to apply? What specializations do you have some interest in? Particularly if you're an MA applicant, we don't expect you to be sure about everything. But it's always nice to see the link between your concerns and our expertise--the people, programs, etc. that you think might work for you.
5) Your writing sample should be clear, clean, and focused. I have been a professor for far longer than I care to remember and I have yet to meet an undergraduate whose theory of communication I wish to read. Generally, the best writing samples are concrete; they study a particular process, case, instance, or whatever. They show us that you can review a literature--even if small--and that you can understand a communicative event with reference to that literature. In other words, show us that you can--or have the potential--to do research. The best samples are clean; if you cannot avoid typos, errors, problems in this paper, when can we expect you to be clean? Come on. Proofread. Finally, show us you can make an argument. If you can do that, everything else will follow.
Oh, and if you're a forensics geek--I was one--don't just send along your rhet. crit. The speech has jargon, lingo, stuff that does not make for a nice writing sample, however much it may help you to kick the ass of some punk ISU competitor :). So, make it a paper--not a speech.
Finally, above all, do not anger our professional staff. You treat our invaluable professionals like crap, then we don't want you. And I'm willing to bet that's true everywhere.
So, some thoughts. Love to have you apply. Don't want to read your 75 page honor's thesis--can't do it, as a matter of fact. Don't really care about your childhood--sorry. We're not friends yet. Be clear, professional, succinct. Leave us wanting more. Because that's what you want to have happen--you want us to admit you.