I'm writing/designing a short comic for this right now, and I would probably give the same tips that have been given already. So instead maybe I'll try sharing my thought process that I'm working through. It might help someone figure out a way to process their short story too? We'll see haha
Since short comics tend to give you a limited amount of time to invest a reader into the story, I tend to focus on asking questions about one thing specifically.
What emotion do you want to leave readers with in your story?
Do you wanna spook people? Make them feel inspired? Have them deep in thought about what they read?
Are there stories out there that give you that emotion?
I'm not telling you to copy them, just understand them. Learn how they managed to invoke those feelings in you with the way they wrote their scenes or paced their panels.
What personally gives you these emotions?
Base it off your experiences and personal interests. Do you love stories about perseverance against the odds? Do you love exploring your fears? Ideas may even come to you quicker if it's based on things that interest you.
I hope these questions help some of you get started! Best of luck to everyone participating! 
