If you're not
completely satisfied, I ought to say that you should be. Whatever you feel like you're missing... well, do something about it. Just like I am doing... oh, this is not referring to the fact that I'm posting this post at work.
Children's book, eh, Undead? In a way, you're right, but it's harder than you may imagine. You have to consider the simple mind of a child in that case, which is quite hard in general. Not to mention that it also depends on what age you are aiming for. Telling a story, for example, is hard enough as it is.
Trying to think as simple minded as a young child is much harder than most people think. I, for one, would never be able to write a children's book. Not only do I force situations in my stories to be far more serious for a mere child to understand, but I also try to strive for a plot that can are supposed to interest adults. If, and only if is an exception of that.
Tenebrae, you always have to come up with a good story line. This has nothing (in specific) to do with a fantasy-story. Unless you are more skilled than most amateur writers and able to write an interesting story from a cliche concept. Not too long ago (I can't say recently anymore, as it has been a few months now) I've read a story online. You could call it a 'Drama / Romance / Humor / Sports', if necessary. Normally, you could say that it would push against my favorite genres of amateur writers, especially when they are around my own age. The basic concept of the story was as cliche as anything. As a matter of fact, I can describe it in a few simple words:
1. Boy moves to another city.
2. Meets up with a girl.
3. Learns that she is just as skilled as he is in a specific sport.
4. They fall in love.
5. They get a few problems.
6. They solve them.
7. And they live happy ever after.
That's about everything that happened in the story. One thing that made it remarkable was that they gave quite a lot of character development to the supporting characters. But as I said, an extremely cliche concept, yet it might just be the best story I've ever read of that genre. What made it so special, you may ask. The main character was gay.
Writing a story that has no... or rather, very little limits is fun for a while. But after some time, you are going to set limits for yourself, making it very little different from a realistic story. I prefer to have those limits premade, therefore that I write a realistic story in the modern times, preferrable about times I personally know.
If you don't set those limits for yourself, then it remains very easy to make the story. There is nothing you have to keep yourself on, except the characters and the basic plot you are trying to develop... and of course, the normal other stuff. This all has to be done too in a normal story, except that the big difference a fantasy story has is the fact that you have full control over the enviroment and the people. You have far too much influence, which can make your story... or world, actually, quite limitless.
You say that you still need a good underlying story to support it still. That is true, I won't deny that, but there is no difference in any other story. Even a children's book needs a (preferrable good) underlying story.
You also said "when you think about it, a main character who is invincible and all powerful is kinda boring," but I believe that I am able to write a decent story about a
main character like that. You can write something good of just about anything.
