write interactive fiction

I have the Inform designers manual and have a good enough grasp of the language to get me started and to work out the more complicated bits as required. Programming is not the problem, writing is. Its incredibly difficult to write something which is both interesting and interactive. While I don’t mind rail-roading the player slightly (a la Photopia) they still need the drive to advance the plot in a consistent manner. Puzzles (If there will be puzzles) must be logical, both in terms of solution and integration into the game world and plot. I also need to play more IF, I’ve slipped recently due to time constraints.