The last few years I've been lucky enough to embark on some wonderful writing courses: Writehereuk's Manchester course taught by Andrew Michael Hurley and CBCreative's Short Story course taught by Cynan Jones. A few editing tips I picked up on the courses have proved invaluable and are listed here.
Search your manuscript for words ending in ly.
Who knew anything ending in ly could be so pesky. Well it turns out these are likely to be the adverbs you could replace with more powerful action words. For instance, the door opened slowly, with the door crept open.
Does the scene really move the story on
I actually learned this one from studying film at university. A story that is filmed has to be condensed, so only the most important scenes, the ones that move the story on, survive the cutting room floor. Ask yourself, does a scene move the story on and if it doesn't will it survive the cutting room floor?
Search your manuscript for negative words: can't, won't, don't
And find a more powerful positive verb. For example, she won't do that, to she avoids that.
Remove redundant words in a sentence
Cut out clutter or unnecessary repetition. There's a great list of unnecessary words here.
Push out the prepositions and turn them into possessives
Search for words that are prepositions like for, in, of, to, or. These are words that cannot stand along. If you can replace them with a more powerful word or a possessive you will make the sentence stronger. For example, the cat that belonged to your father is really just your father's cat.