Ready for another tip?
When you're stuck with a story, there are a few ways to fix it.
The first way is to try to fix it yourself. Generally, this means leaving the story alone for a while and then coming back at it with fresh eyes. “A while” can be a few hours or a few days/weeks. It doesn't matter. It will take as long as it will take for you to find your way past your story problem. (Most of the time, this can be alleviated by plotting an issue out first. You can cut a lot of problems off at the pass by doing as much preliminary work as possible. Then it just becomes a matter of sitting down and doing the work.)
If you're working against a deadline and don't have the luxury to wait, another method is to talk to your storytelling friends. If you're not part of a trusted circle of friends, find one, or join one. They'll help you out of a storytelling bind by giving you the perspective you don't have. The ideas may be good, bad, or terrible—the main thrust isn't to use their ideas (although you can), but to get your into a different head space so can see the problem and fix it.
The third way may be best. (And I don't say this out of enlightened self-interest.) Hopefully, you have an editor onboard. Part of their job is to find the problems and to help you through them in order to make the best book you possibly can. If you're self-publishing, this can be an expensive way to go, but it should be part of the editor's service.
(I do believe that every project needs an editor. It doesn't matter where you are with your skills. Editors will save your storytelling life.)
And there's your tip.