Create a folder in /var/mobile with a random name u can remember it doesnt matter.
Instead of giving step by steps, ill give u the layout (in tutorial tomorrow ill step by step it).
In this ur random folder will be named Random and ur project will be named Project
Ur basically going to mimic iOS folder hierarchy
-Random (located in /var/mobile)
|--control (a file-for info see general development topic Hack Tools Standards)
|--any files you have
To package it to a .deb run:
dpkg-deb -b /path to "Random" Project.deb
The path to random should be /var/mobile/Random (insert folder name u used for random) and the Project Name of your choice gets substituted for Project in Project.deb (and in folders u made earlier)