As for design, I always liked one aspect of ST-Demo's we never really saw on the Amiga. Most Amiga demo's are "film-strip" demos where each scene plays one after another. But some ST-Demos bolted on an interactive "game" as a menu where each "screen" could be selected by entering a room on a platformer, or a building in a 3D landscape etc.
That concept was more used on Atari ST, Amstrad CPC or MSX, there's a megademo on Amiga with such menu, tho: Darkness Megademo
Crown: Do you have any examples of your work ?