I've been softly avoiding giving out application advice. People interested in my own insane journey through the bowels of the admissions system are advised to go back through the 2009 posts. That said, in a recent conversation with a grad school applicant I came up with three questions that are worthwhile for determining which schools to apply to. Obviously there are an infinite number of questions to ask, but these three are a good place to start.
1) Would I actually move to the place where the school is located?
I flat-out ruled out some schools in places I didn't want to live. If you can't see yourself packing up and moving to New York City, why even apply to schools there? Location is more important to some than others, but do your research on the place, because you will occasionally leave campus. Think about where you'd be willing to move ahead of time.
A lot of applicants treat grad school admissions like undergraduate admissions -- send out a bunch of apps, then go on the prospective student visit and make a decision on the location. Bad plan! Don't waste money on applications for schools you'd never in a million years go to.
2) Is there someone, or multiple someones, to work with at the school?
Online faculty profiles are your friend. Email and phone contact with professors is even better. Sometimes faculty will be interested int the project but simply can't take on new students: they are going on leave, they have 82 students already, there's no room for a new student on the grant, etc. Find out this information before you apply.
My experience is that 95% of professors aren't bothered by a short, polite email inquiring about their graduate advising availability. So long as you aren't spamming them, this won't stymie your application in any way, and in some fields it can radically boost your admissions chances. If there's no professors around to take on your project, most schools won't admit you because there's no advising structure in place for you. Anticipate and take action to prevent this.
3) Is the program what I need, both in the next few years and for my career?
In this insane world of 12% acceptance rates, I understand the desire to gain acceptance to any program and enroll faster than you can say "is there funding?". That's because the regret of attending a school that doesn't have a solid program for your needs comes much later, like 4 years down the road when you realize your department specializes in research and you really want to teach. Whoopses!
This is 100% preventable. Do your research. Ask about placement. Ask about how the program works. Try to talk to graduate students there. If nothing they are saying appeals to you, don't apply.
The end result is this: if you only apply to schools you'd actually go to and do well at, you really only need the one acceptance to be on your way. The only general advice I can give is to try to remain sane long enough to figure out the answers to these questions. Don't worry, I'll have lots of advice on how to make the months pass as you're waiting to hear back!