The father of one of my students asked me if I could provide his son with a short guide his son could keep near his computer and use while writing. Here it my suggestion.
Create a detailed prewriting organizer before you write. Use it.
Make sure you follow directions if you are writing a response. Cite? Paraphrase? Summarize? Analyze? Two instances? Three?
Write the thesis sentence first before you write any other sentence if you are writing an essay.
Decide who your main character is and the problem he or she will face before you write your first sentence if you are writing a narrative.
Read your first draft aloud. Does every sentence make sense? Do you follow your organizer? If something is missing, include it. If something is irrelevant, delete it.
Make sure every body paragraph supports the thesis of your essay.
Make sure every action moves the main character closer to solving his or her problem in your narrative.
Identify weak or overused verbs and replace them with specific verbs.
Identify and vary sentence structures. Especially include complicated simple sentences and complex sentences.
Show, don’t tell. If you are concluding, you are telling.
Search for your typical grammar mistakes and fix them.
Add more precise details such as names, numbers, dates, locations, direct quotes, dialog, examples, thoughts, precise descriptions and sensory information.
Do revise. First drafts are seldom good enough.