"Completeness" of Support
It may seem obvious, but readers will notice if you leave out information that is important to the kind of opinion you are supporting. Complex problems generate complicated opinions, but writers rarely can generate all of the necessary support in one episode of writing. Schedule time to write in multiple sessions, talk to Writing Center tutors and classmates and your instructor, and recharge your mind's ability to see the topic. Writers who are used to composing complete papers at one sitting usually discover quickly that college-level readers require more from them. Be prepared and make time to expand your composing process over more hours and days than you are used to spending.