This is how I approach designing a CYOA game for Twine:
Genre and Setting
Decide where it is set.
What is happening
simple overview of what will happen. If the player is reacting to
events in the world, then what are those events? If she is to foil the
plot of the evil supergenius, exactly what is that evil supergenius
trying to do.
On the other hand, if the world is carrying on as normal, a simple one sentence description might be enough.
are the meaningful outcomes? Aim for about half a dozen, and try to
have some good aspect to all of them, even if there is a downside too.
You died, but you thwarted the evil genius. Or each outcome could be a
success for a different faction, and the player has influenced which
You might choose to write these out as they will appear in game at this stage.
pages that the player will always go through (or usually go through
or...). Of course, this will depend on your game, maybe there are
broadly two ways through, each with their own set of choke points, the
player does one or the other.
Again, you may choose to write these out as they will appear in game at this stage.
Write that first page!
Join the dots
Now all you have to do is create the pages linking the beginning to the chokepoints to the outcomes. Simples.