Once you have figured out your topic, completed research on it, collected sources, and settled on a thesis, you are ready to start drafting. Duke has a drafting guide that can help from developing an argument to paragraph formation and transitions.
U of Michigan’s online guides can help with the structure of an argument as well as creating introduction, conclusion, and body paragraphs.
If you want to enhance your style, Texas A&M provides resources for:
If you find yourself struggling to hit the length requirement, whether below the minimum or exceeding the maximum, the DU Writing Center’s resource on writing too much or too little can get you on track for the optimal length for your essay.