Automate package creation process.
One of the easiest ways to automate is to use a shell script. Make sure you have a copy of app.mk (under Additional Resources below). Most of the information you need to automate is in the comments inside the file.
In addition, using a Makefile in your project will help you to exclude any files you don't want to be zipped up into your channel - for example: zip files, .psd files, .git and .svn folders etc, as well as including libraries you might not want to store directly in your development project.
If you look on our Developer Forum and search for "Automated Build," several developers have shared ways they have automated builds.