I find I start a story and then get so many ideas that the plot goes off on a tangent. How do I remedy this?
This is sometimes part of the creative process, you’re still discovering what your story is about or exploring the possibilities it contains. If you are asking yourself this question then you’ve already recognised that the story won’t work with the number of ideas going into it and you’re getting to the stage where you need to consider what your story is about, so… it’s important to think about the overall story, the characters in the story and find which ideas will make the characters shine. All the other ideas can be ignored, deleted or, better still, cut and pasted into another word document to maybe use in your next story.
If you’re not sure which idea to take step away from your story for a day or two, then come back to it. It’s surprising how much such a short break can make on the perspective of the story you’re currently writing.