When it comes to music

A person that wants to create good games needs to write music. Don't use stuff that is copyrighted when using downloadable music, even if you own it. For example, adding copyrighted music (like something by Coldplay or any published band/artist) to your domain makes it easy for someone to steal a song.

Write your own. Don't even use FreePlay music. Get a good music writing program and make sure that you have the tools needed (like a keyboard and any additional software/hardware). In case someone dislikes your music, you should add a mute or pause button.

If you're using a Mac, you can use GarageBand. I used to use GarageBand, but now I use Logic Express. Logic is a really great music making program created by Apple. It is available for Mac only, and costs money.

So there you go.