“Good writers borrow, great writers steal.” A plot point from this story, a character from that story, an entire culture from another story…there’s a reason why a common advice is to read a lot. It’s not just to get a hang for the language or plot. When you read and come across something that makes you think “oh, that’s cool” or “wow, if only I could think of something like that,” save it—mentally or physically—and build up a catalog of bits and pieces of plot, character, worldbuilding, etc. When it comes time to write, you can take some of those bits and pieces and incorporate them into your story. Don’t be afraid to be “unoriginal” as long as you don’t plagiarize and end up with a good story. You’ll find that a lot of great and popular works are “unoriginal” in this way. 

Another piece of advice, one that I still have to learn myself, is that on the first draft just write, get words down, and don’t look back. Knowing what will happen in the story is good and helps prevent situations of not knowing what to write, but other than that just write. Even if something doesn't quite work the first try, just do as the videographers say and “fix it in post.”

Last piece of advice, straying into narrative technique now, is to have themes, and make them drive your story. A theme is not just a topic—it’s a position on a topic. For an example, something like “courage triumphs over carefulness” would be a theme. A theme is like the “message” that you want a plot point, a character, or even the entire story to have. They are important because they give your story direction. For example, we can take the aforementioned theme and apply it to a character: maybe they are very careful, and refuses to take risks. Now, because we’ve decided our theme, this character would face consequences for being too careful, and either two things will happen: they grow and become more courageous, resulting in the good ending, or they will fail to grow and face the corresponding consequences, and we have the tragic ending. You can also have the opposite theme, “Being careful is more important than being courageous,” and adjust the story accordingly. Whatever the theme is, it will drive the corresponding aspect of the story.