Well, first, decide on the genre and style you want for your collection. Then, focus on creating unique and engaging characters. Also, pay attention to the pacing and structure of each story to keep the readers hooked.
To create a great short story collection, you need to have a clear vision. Think about what you want to convey through the collection. Also, work on improving your writing skills, especially in terms of dialogue and description. And don't forget to edit and proofread thoroughly to make the stories shine.
Start with a central theme or concept. Come up with a bunch of related story ideas and develop them. Make sure the stories have variety but still fit together.