One needs skills for creative writing short stories. Writing short stories is a profession for many writers around the world. There are talented writers in many languages and in many countries. The moral of the short story and the characterisation should be well structured well in advance. The most important aspect of writing short story is very good command over the language in which you want to write your short story. There are many differences between two synonymous words. The word SADNESS could not be used in place of another word SARROW, though they are synonymous words as per the thesaurus. You should have the high command over English language in order to make the characters as expressive as they should be. That alone will justify the characters.