A little while back, there was a free online workshop by a writer of one of the Choose Your Own Adventure books. 

In this, she walked viewers through how they can start planning their own. 

First, let's learn a bit about the book she wrote.

Now, let's start doing some planning. In this video, Rana talks about dividing a planning page into 4 sections. You can use actual paper for this if you want, or you can work digitally.

Your choice.

The next section of the planning document relates to the setting of your story.

Follow along with Rana.

The third section relates to the conflict of your story.

The final part of your planning relates to the choices in your story, specifically focusing on your character's first choice.

Where do you go from here?

In this final section, Rana gives some advice on what you'd do next. Keep in mind, this is based on her method and her perspective. You may have other ideas, and that's fine.