1) Repetitive Words—Common culprits here include ‘filler’ words like really or just. However, all writers have their own quirks and favoured words/phrases. Once you recognise these, you can search for them. Do a Find and highlight in Word. You’ll probably be surprised how often they crop up, and how many you can change or cut.
2) Repetitive Paragraphs—Watch how you start your paragraphs. Do they all begin in the same manner and/or with the same word? If so, try to change things up a little. The same goes for the sentences within the paragraph. Ensure they don’t all commence identically.
3) Repetitive Actions—Are your characters always smiling or walking? As you read through the story, check for these repetitive actions and try either eliminating some completely or changing for a synonym. Often the latter fix also adds to the impact of a scene. Consider, for example, the different feeling suggested by ambling, walking, striding and dashing.