"I have a feeling we will win this time"
Okay, you've got your effects. If they are your first ones, they're probably very, very crappy but they're effects nevertheless. Let's say you've got metaballs, a textureplasma, some tunnels and a growing fractal tree-thing. You made the textures yourself, using non-coder colours. Your graphician has made a few pictures, depicting different things: A motorcycle, a dragon and a semi-nude lady. They're all quite good, at least in your opinion. Your musician has made a trance song. Now what?
Now you're in trouble. The traditional demoscene thing would be to put the effects after each other, put the song playing in the background and in between effects, show the pictures. This is a Bad Thing. Why? Because it lacks consistency and will likely end up looking like crap. Unless the effects are really good, and even then it could use some design.
Check out any good demo. Really, any demo you think is really good will do. What do you see? Consistency. Two quick examples: Protozoa by Kewlers is very organic and mostly green, while Dreamchild by ASD is dreamy and blue. What do you have? A motorcycle, a dragon and a semi-nude lady. And a tree. What have they got to do with each other? Nothing. Absolutely nothing. (Unless the guy driving a motorcycle sees a dragon, panics and drives off the road, hits a tree, dies and ends up in Heaven with the nude girl. But you shouldn't count on that)
You have to decide what kind of a demo you want to do. If it's going to be a techno demo, ditch the pictures and the fractal-tree effect, concentrate on making it aggressive and full of adrenaline. If you opt for a more mellow route, lose the motorcycle, keep the rest of the pictures and work on your effects until they are mellow. And tell your musician to make a chill-out tune. Do anything, as long as it has a guiding thought.
A better way of doing things is just make stuff, then have a meeting and decide what sort of thing you want to pursue. Do you want to make a techno demo, or a chill-out demo, or a minimalistic anti-capitalistic black and white demo with trip-hop in the background and a real message? Decide this, and then think what would you like to see in such a demo.