This is just a small idea I had but I think it could be quite effective.
Fantasy or 40k players; the basic concept is that you and your opponent each create an army of a chosen points limit, you dont tell the other person what you have.
Then just before the battle begins you trade army lists and fight with the army your opponents has created.
This would create a whole new range of questions you need to ask;
How do I use this new force? How is my opponents going to use the force I've given him? What do they expect me to do?
And if you and your opponent both decide on a really un-synergetic list that can just add to the tactics required. Altogether I think that this type of game will make players re-consider how they build armies in the future.
What are the publics thoughts on this?