What's a metapackage?

A metapackage is a package which doesn't have any files to install, but depends on other files to make sure they are installed. A good example of a metapackage would be the gnome package in the Debian repos.

Why would you want to make one?

In my case, I need to make an easy way to get my Debian2Debian server/client setup. I need to install certain packages and scrit some stuff afterwards. Maybe you want to make one so that setting up a copy of your desktop on another computer will be easy. MAybe you just want to help a friend install some packages.

The process

This is really easy. Create a directory to hold your files and name it after the package.
mkdir mypackage
Fill the directory with the proper structure
mkdir mypackage/DEBIAN
touch mypackage/DEBIAN/control

Edit the control file so that it looks like this:
Package: mypackage
Version: 0.10
Section: main
Priority: optional
Architecture: all
Depends:
Installed-Size:
Maintainer: Daeng Bo
Description: A metapackage for Daeng
 Detailed description (optional, and notice the leading space)

Create the package by running
dpkg --build mypackage
from outside the directory.

Congratulations! You're finished. Install your .deb or send it to a friend.