It's bedtime and instead of reading a princess book the kids have already heard a million times before, you start to mix it up. You get all JK Rowlings. You make up a story, and not only that, but you make it a serial story, so that you tell another part each night.
But you're not JK Rowlings. So whyyyy did you do this to yourself?
If you're already knee-deep in it (like me), here are some suggestions to help you out of the never-ending story hole.
1) Do not, under any circumstances, make the main characters your kids.
It seems like a great idea at the time. In fact, your kids may even request it. And why not allow them to even further relate to the crappy characters you're making up on the fly? Two reasons: 1) they shouldn't need it. They'll be able to relate to the characters whether they share physical features and names or not. 2) If you make them your kids, and then you give them, say, magical floating powers when they wanted, oh, let's just use this random example, hugging to make people feel better powers...now you've got a tantrum or a sulk on your hands, and it's like, yo, who is even telling this story, and how are you upset about floating powers anyway, they are obviously awesome.
2) Avoid anything that could be scary, even a little scary.
This is hard because any sort of conflict or suspense scene or anything at all where motives could be questioned, where good guys may not even always be good, all these things can lead to the dreaded, "mama, I'm too scared to go to sleep." So be prepared for your story to be nothing but parties and singing and specialness. They will really suck, but I'm saying my kids couldn't even handle being thrown in a dark room for two seconds before the purple fairy rescued them with a vine. That was too scary for them. Great. Surprise parties and pretty dresses it is. (Just kidding, though. Tomorrow, I'm venturing into ogre and guard dog territory as the girls climb a mountain to get the gold coins to pay the person keeping the princess fairy locked up. I DON'T CARE ANYMORE. AFTER A WEEK OF FRILLY NONSENSE, I AM TELLING THE STORY.
Sweet dreams, kids.