There are a few simple tricks:
1) Write something simple. A short story doesn't require a lot of details or characters or sweeping Big Ideas to captivate a reader. Just write, something with a beginning, an event, and an end.
2) Write something for your character. You may, in your lifetime, invent a person that you think is cool and/or witty and/or fun to be with. So, give that character a moment in time to be all that. Hopefully other people will read it and like your character too.
3) Write something that gets an idea from thought to paper. Don't let the idea stay bottled up in your head. Commit to paper. Read it with your own eyes, and find the language to make that idea flourish.
5) Stay consistent.