This is how I create apt cdrom in order to save disk spaces. I do this when my /var/cache/apt/archives reach 700Mb, so I create a cdrom that I will add to /etc/atp/sources.list with apt-cdrom add.
I don’t know if it’s the right Debian way but it works. If you have something better, use the comments. 🙂
I move all deb files into a directory (lets call it /home/davide/cd), then
sudo dpkg-scanpackages /home/davide/cd /dev/null | gzip /home/davide/cd/Packages.gz
Then take all the files within the /home/davide/cd directory and burn a cd.