Story Outlines
Here are a few different structures I've played around with.
Three-act structure
Used most commonly when writing movie scripts, the three-act structure helps split a story into a beginning, middle, and end — though it's much more detailed than that. This kind of structure will help you keep things moving in your story, especially when the plot might fall flat. That being said, while this outline is good for reminding you and your readers about what's at stake, it's important not to rely on it too strongly, otherwise moments might seem forced. The link below includes a graphic detailing the different components of the three-act structure, as well as its shortfalls to avoid.
A, B, and C Storylines
For a story to be multidimensional, it should have more than one plot line. Another structure that has also been used in screenwriting is labeling these different plot lines as "A," "B," or "C" in order of importance. The "A" storyline is what most of the story will be about, focusing on your protagonist and their goals. The "B" storyline focuses on a side character, allowing readers to learn about the protagonist and their world from a different source. Finally, the "C" storyline is a slower thread throughout the story, either providing comedic relief or some other purpose. Each of these threads should all braid together to create a full and nuanced story. Check the link below for more details.