Now that we've been doing Tangled Fiction for a couple months now and I've had the chance to write two story starts for Natalie and Lacey to finish, I've made some discoveries about plotting and revealing information.
When you're writing something that someone else has to continue without knowing what's supposed to come next your first instinct is to put in enough details to explain what it is you're doing. But you soon realize that if you do that, the next writer either has nowhere to go because you already gave up all the cool info and twists, or is locked into your idea, which is the opposite of collaboration (unless you use James Frey's definition of the word) and what you've written is mostly telling and infodump with perhaps a side of interesting character.
You learn that in order to give the next writer a chance to shine, and to give the story a shot at being all it can be, you have to leave threads dangling and hint at things without explaining them. You have to trust your partners, and your readers to pick up on the subtle cues, and to want to keep reading to find out what they mean.
In a word, you're doing exactly what you're supposed to be doing when you write a book all by yourself!
You know that feeling you get when you're starting a book, (or short story, or introducing a new character) where you feel like you have to get ALL the necessary info out so readers will get what you're doing and LOVE it? Well, that feeling is wrong. Those writing books - the ones that say don't reveal anything until it's absolutely necessary are right.
It took until I had to take an idea, set it up, and then let it go for me to really understand how that works. When I write an opening to one of our shorts, like my most recent one, KISS OF DEATH, I start with an idea:
What if there was a girl so beautiful that every boy who saw her was compelled to kiss her? What if her lips were poisonous?
Then I have to do some world-building, some plotting, and I have to make sure I leave something for the next writer. In the case of KISS OF DEATH I had A LOT of ideas. There was so much I wanted to (and did in the first draft) explain. I knew how Rosemina came to be cursed. I knew what she did all day while she was home alone. I knew what the Queen really thought about her. I knew what happened after my section ended. But I cut all of those things because they would work better if they were revealed later on or in an active way. I trusted that I had an interesting predicament (Everyone wants to kiss her. Everyone that kisses her dies. And because of that, people want her dead.) and that people would want to keep reading to find out what happens next.
This is the key when plotting your story and maintaining your pace. Drop hints. Dangle potential plot twists, make your reader excited and curious to see what happens next. Let them form opinions about why a character says or does something, and then reveal the info when it will be the most active, the most important, the most mindblowing thing that could happen at that moment. Save something for later. (And, as I always say trust your reader It's scary, but you'll be glad you did.