To figure out how to write a good article, read tons of good articles; to figure out how to write a good short story, read tons of good short stories; to figure out how to write a good master's thesis, try reading some great master's theses in your field (or at least skim them for structure and to see how they develop and maintain their arguments)! Look in particular for the ones which have won awards (departmental or otherwise) and the ones written by people who would go on to be tenured/tenure-track professors.