InstaDMG Best Practices

Hi All Have just started using InstaDMG and am blown away by what it can do. I've successfully built several test images, however as I add more and more packages (usually my own) I'm finding some are failing. I read the blurb on the Office 2011 installer and got that working correctly which led me to believe that paths in my packages are the culprit. What is best practice here? If I add "$3" to the beginning of my scripts (ala the Office installer fix) should I be safe? How will that work if the package is installed manually? (I am sketchy on the $1 $2 $3 usage) Also, I am compiling a 'first boot' script that sets a whole bunch of settings (ARD, system preference settings, sleep settings etc), what is best practice here? What should be set by a first run script as apposed to being packaged and installed as part of the initial build? Thanks for any guidance. -- Laura