The tool's interface is pretty straightforward and you can start using it in a matter of seconds. You just need to select the input files and the output .exe, then start the process.
Additionally, you can choose a password or even an icon for the final output file. However, both are simply secondary complements.
Smart Packer has a very particular practical application, but if you know how to use it you'll save yourself lots of time and avoid lots of headaches.