It is going to be a quick one. There is a simple checklist of things that you can use to help Packager be your friend.
1. Don’t include stuff you don’t need to. I see people including the whole folder with system templates instead of adding only custom templates or just changed fields on the system templates if there are any.
2. Use PChex component to verify package integrity.
3. Prefer dynamic sources over static sources. Kerry describes why here.
4. Disable search index to improve performance of package installation.
5. Get yourself familiar with the Installation Options. Use “Overwrite” very, very carefully as it may overwrite the branches.
6. Predefine those installation options. If somebody else is going to install your package, you don’t want them to choose for you.
7. Though readme gets ignored in most cases, do your best to supply the installation information or post-install directions with the package metadata.
8. Make sure to save the package project (xml file).
I realize that this may not be a complete list, so please feel free to share your experience and do comment.
Thanks!