Mastering is the last process in a project, taking all of the mixed songs on an album and slightly adjusting EQ's and levels of each song to make everything sound as even as possible when you listen to the CD. This process also involves compression in order to make the CD as "hot" as possible and still sound pleasant to listen to. I master my own recordings as well as many other recordings that come from other recording studios. I utilize all tools I have available including tube gear and analog tape.
If you are sending me a project to master:
1) Send the highest sample rate and bit depth you have been working with. No MP3's! I also prefer a data disc or FTP transfer over an audio CD. Remember, an audio CD is fixed at 44.1K 16 bit!
2) It is best to take all 2 mix buss compression off of the files you are sending me, particularly maximization or limiting compression. The reason being, I need as much dynamic room to work with even with EQ. That gives me the most options to make your project sound great!
3) I need all of your information including artist name, album title, and all song titles EXACTLY the way you want it to read for CD Text encoding. One note: CD text is NOT the same as the information that comes up in iTunes. The iTunes titles are handled by file recognition though a company called Gracenote. That all happens through the iTunes process.