Here's a question I got via email this morning:
What one piece of advice would you give to someone starting out at producing/mixing music? I can't quite decide if I'd rather wear the producer's hat or the mixing engineer's hat. I ask because I want to take music production more seriously, but I am a complete novice. Everyone wants to be a producer, but good mixers are hard to find. It's a skill I'd love to possess, but I don't know if I could ever become great like you and others. It's an art. I suppose we all learn somehow.
There is no simple answer to your question, but if you want just one piece of advice, I'd say the key is PRACTICE!
Becoming a great mixing engineer is like becoming a great musician. It's not that hard to learn the basic technical skills you need. But, the only way you get really good at mixing, or playing an instrument (or singing), is to constantly practice and work on improving your skills. There needs to be some level of natural ability as well. Mixing is just as creative as it is technical, and involves being able to listen in a certain way and come up with creative ways to not only make things sound good, but to also enhance the mix and take it to the next level. Lots of people can become very technically proficient at guitar or piano, but to be able to add feeling and emotion to the playing, and be truly creative, goes way beyond technical skill, and is really not something that can be taught. Mixing is the same. Many people can become great technical mixers, but to get to that next level you have to have that musical creativity that really can't be taught.
Best thing you can do is practice mixing as much as you possibly can. Offer to mix things for free to get some material to practice with and to start building up your name. It's not something you are going to pull off in a few months or even a year, and you are never "there"... you just keep learning and getting better the more you work at it (just like an instrument).
If you understand music, that's a bonus, as you need a strong musical sense to be a great mixing engineer. If you don't play any instruments, you might want to consider trying to learn an instrument or two... at least the basics. Knowing about music and the basics of playing any instrument will help you better communicate with the musicians, and give you a better musical sense. You can't be a master of everything, though, unless you just have tons of free time, so I'd mostly concentrate on mixing as much as possible, and just learn enough of an instrument to help you develop a good musical sense and be able to communicate better with musicians.
Of course, you are probably still pretty young, so you've got plenty of time to work at both and develop both your musical and mixing skills. I played trumpet and piano since a very early age, and didn't start getting into recording until the second half of college (this was before everyone had computers, and recording was still done with tape machines, so we didn't have easy access to recording tools back then).
Next to practicing and natural ability, or possibly even more important, is your people skills. This is a service business, so how well you get along with clients is probably more important than how good you are at mixing. If you can't get along with a wide range of personality types, and learn how to give them the results that they want (as opposed to what you think is "right"), then you won't get very far. I've seen many young engineers who think they know it all, who refuse to give into the client's wishes, insisting that they know better than the client. I'm not saying that you can't disagree or defend your choices, but, in the end, it's the client who is paying you, and the client whose name will be on the product (with digital downloads especially, nobody knows who mixed a track). In the end, you have to give in to the client's wishes. There is no "right" or "wrong" in recording and mixing. Sometimes things that you think sound bad may end up being a huge hit, either because of that "bad" sound, or at least in spite of it. Don't be afraid to disagree and present your opinions, but you need to do it in a friendly and non-combative way, in order to maintain a good relationship and preserve your reputation as someone who is easy to work with. Also, no matter how crazy or "wrong" a client's idea may sound, don't be afraid to try it. You may be pleasantly surprised at the results. Or, you try it the client's way and they realize it wasn't a good idea, and you go back to something else. There is no harm in trying.
On another note, if you haven't gone to college yet, I would very strongly suggest to major in some sort of technical degree, such as a computer or electronics type degree. That type of degree will come in VERY handy for any type of music production, recording, or mixing pursuit, since it's all computers and electronics. Plus, it gives you something to fall back on. Most likely, you will need to get some type of "day job" to support yourself while you try to develop a name for yourself. The music biz is only getting tougher, and there isn't a lot of work to go around, and too many "producers" and "mixing engineers" out there fighting for a relatively small amount of work.
Finally, I would also suggest that you don't have to do one or the other. You can be a producer as well as a mixing engineer and recording engineer. Those areas are all related. Pretty much everything I said above also applies if you substitute "producer" for "mixing engineer". I taught myself recording/mixing while in college and in the Navy, and when I landed the job at the big studio, "Recording Engineer" encompassed recording, mixing, and sometimes even mastering. We pretty much did everything required of us, which sometimes involved some producing as well. I developed into being a decent music producer as well. My strengths, however, are definitely recording and mixing. Although I prefer mixing these days, I still love recording and producing as well. You need to at least understand the basics of recording to be a good mixing engineer. Understanding how instruments, such as drum kits, are typically recorded, will help you make better sense of the tracks sent to you and help you work out phase issues and other problems you may be presented with when giving tracks recorded by people at home or by less experienced engineers.