Mastering in Garageband is an important task that comes at the end of creating a new song. One of my favorite techniques for getting good mastering results in Garageband is to use a multi function plugin called OZONE. I use this plug in on the master track to output my song to iTunes or to a hi resolution AIFF file. Another good technique is to output your song to an AIFF stereo file, and then create a new garageband file, and import this AIFF file. Then apply OZONE to the stereo master file and output again to your final mastered file for CD production or input into iTunes!
Give it a try... and keep making music... it's good for the soul!
tags: mastering, garageband