Omit Needless Words. In short, if there's a word in the sentence that can be removed without damaging the thought, it should be removed. That alone can dramatically improve your writing.
Most people think of editing right on the hard copy, paper and ink, with pen in hand. Okay, feel free to do that. Personally, I like to use the computer screen. Remember, if you make the changes on the screen, they're made. No one has to re-enter the material you've just edited.
Search the document for the word 'that.' Almost 75% of the time this word can be eliminated without changing the thought of the sentence. Next comes the word 'then.' Get rid of it if you can.
Search for the two letters 'ly' and you'll find most of the adverbs in your work. An adverb modifies a verb. He didn't just run, he ran quickly. Remove the adverbs. Remove them and use a better verb. Get rid of the adverbs. Don't forget to do a search for 'ly.' as well. Adverbs can turn up at the end of a sentence, frequently.
Try and eliminate; usually, nearly, barely. Also, be wary of 'often' and 'seems.' If words, phrases or entire sentences can be removed without affecting the work, then remove them. Do a quick word count before you begin. Your goal is to have 10 percent fewer words than when you started... and watch your writing get better and better.