On grad school:
Understand what grad school is and isn't, and what you're trying to get out of it. It's not a ticket to a college teaching gig, although a DMA/PhD from a top 10ish school seems to be basically a prerequisite for actually getting a college teaching job. It's not a guarantee of security, or a job, or commissions. At its best, it's a group of students and faculty you can learn from and who get to know your work, a place to meet friends and collaborators, and a temporary source of externally imposed structure, all of which are great. At its worst, it's a money-sucking debt-hole in a town you hate with people that make you angry. You definitely don't need grad school to make yourself a better composer or build your career, and ultimately you will need to figure out how to do all of these things in "the real world" regardless of whether you go to grad school or not. However, a good program makes certain things a hell of a lot easier. Here are some numbered thoughts:
1) DON'T GET HUGELY INTO DEBT for an advanced music degree. Just don't. There just aren't enough jobs to justify it, and you can (and should) do plenty outside of school for your comp career. I know composers who got saddled with debt and basically stopped writing after grad school because they had to work so much to pay off their loans. I also know folks who saved up for a couple years and continued to work their asses off in outside jobs throughout grad school to cough up the $25k every year. If you don't get into a good program you can reasonably afford, keep working, save, get better, organize more concerts, perform more, and apply again the next year.
2) KNOW YOUR CHICKEN. Like I said, at its best grad school is primarily source of interesting and useful people. So do your research. Look up faculty members to see who's doing stuff you're interested in (emailing them is a mixed bag in my experience, but at the very least can be helpful in determining if someone's an asshole). Internet stalk and then email current or past students to see what they're like and how they like the program. If you're into research, see what people are researching. If you're into an extra-academic career, see if people are getting commissions, starting ensembles, and what kind of gigs they're doing. Basically just be an internet stalker. Also look at program offerings and call financial aid offices. Visit places if you can and get a real sense of what the place is like. Know what you're getting into, whether you'd be a good fit there, and whether you can afford it.
3) JOB PROSPECTS. Post-Masters, much to my disappointment, I did not immediately receive two years worth of paid commissions and a college teaching job. I moved to Brooklyn and spent a year essentially doing the same work I was doing pre-Masters, and, as with my post-Pomona move to SF, was broke and stressed a lot. However, occasionally people also paid me to write or perform, which they very rarely did pre-Masters, and that work has gradually become a legit income stream. I chalk that up to connections, reputation, and being a way better composer and guitarist than I used to be, all of which are things I cultivated at Yale (and Bang on a Can, but more on that shortly), but which are all also things I have cultivated outside of school too.
4) DON'T STOP WHAT YOU'RE DOING. Regardless of grad school, I wouldn't have any the connections and opportunities I have now if I hadn't continued doing all the stuff from my last blog post. Never stop doing what you love, never stop getting better, never stop going to shows and meeting people, never stop organizing your own stuff.
4) SUMMER FESTIVALS. This one should even go in the Food and Music post, because they can be so goddamned helpful. I credit a three-week program I did at CSU Fresno with really teaching me how to write for instruments and make legit scores, and in so doing, getting me into grad school. I credit the two summers I spent at the Bang on a Can Summer Festival with launching my career in New York - a huge number of my paid commissions and most of my paid performance work so far has been through connections I made there. I would look particularly at ones that emphasize composer-performer interaction, and preferably ones with faculty from schools you're interested in. Yes, they can be expensive and that sucks (although way less expensive than a grad school without a good financial aid program). As always, hierarchy of needs. But if you can figure out how to make it work financially, it's absolutely a good investment early in your career. They'll help build your chops and portfolio, and potentially connect you with the person deciding whether or not to admit you to their school, or commission a piece from you, or hire you as a performer. It's huge.
5) If you're interested in making yourself crazy by thinking even more about this, a while back Aaron Gervais also wrote a very interesting series of blog posts on this topic that you could go read. Maybe someday I'll get to discuss this with him.
Them's the thoughts on grad school. Look forward to part 4, where I just ramble on about some general thoughts I have about composing and performing.