Advice for free!

Some of the important things I've learnt over the years, things I've done which I recommend, and things which I wish I'd done when I was at school:

• Learn Piano, or a Mallet Percussion Instrument (xylophone / glockenspiel). This is one thing I wish I had done when I was at school.  It has all sorts of benefits, even if you don't decide to be a full on classical pianist or if you don't want to perform on piano.  It's good for your reading, it's the best way to begin to understand harmony and music theory, it's good for your coordination and reading, and lots of other things. 
• Practise.  
• Don't ever think "I'll have more time to practise when I'm older" You won't, get some practise done today.  
• Don't ever think "I'm playing in school bands and with my friends, that counts as my practise time".  Playing with people is very important, do it, but there are things you just need to practise on your own.
• Say yes to everything (for a while, anyway).   When I was at school I used to agree to do just about any musical activity that came along.  Rock bands, playing for the school band, accompanying the school choir, playing in someone's HSC Music exams, playing in the local music theatre group's production, and so on.  Don't just do what you think is going to be cool or fun.  If you have a good music teacher and they want you to be in a particular ensemble, listen to them.
• Be enthusiastic about what you're doing and have a good attitude.  There's nothing worse than playing music with people who don't want to be there.  Always enjoy yourself when you play music, or if you're not enjoying it, at least let other people enjoy it.  
• Learn to read...well!   Learning to read music to a good standard (sight read, that is) will open up some doors to good opportunities, and it will make life easier.  Reading isn't the fun part of playing music, but it does lead you to the fun part. 
• Form good habits.  This is something I'm always trying to work on with my students.  Try to have a good grip every time you play, not just when your teacher is sitting there telling you to do it properly.  When you play something easy, make sure your grip is correct. When you practise at home, make sure your grip is correct.  Practising technique isn't the fun part of playing music, but it leads you to the fun part.