Planning a Twine Game

This is how I approach designing a CYOA game for Twine:

Genre and Setting

Decide where it is set.

What is happening

A 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.

Outcomes

What 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 one.

You might choose to write these out as they will appear in game at this stage.

Choke points

Identify 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.

A beginning

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.