Key parts of story telling are easy to define off the top of your head. You need a good plot arc that meets certain requirements. You need to ensure that your core cast of characters are varied and work well together. There’s a definite need for twists and turns to maintain a smooth pace. From there it’s mostly a matter of making sure that your story is readable and has a good flow.
But what about the interactions and dialogue? A lot of people tend to struggle with this aspect in their first few years and, even after quite a bit of experience, intermediate writers still encounter problems. The issue doesn’t present itself too much in the core characters, they’re typically the ones you’ve spent so long working on fleshing out that you know almost everything they should say or do. Plenty of people have tutorials out there telling you how to build characters like snowflakes or how to “interview” them to make them more real to you. So long as you follow that and you make sure your characters are well fleshed out, they’ll interact just fine. But that just handles your core, and frankly that’s not where the most egregious problems show up.
Where do those biggest problems appear then? When your protagonist encounters a nobody…