Try to set aside your draft for a day or two before revising. This makes it easier to view your work objectively and see any gaps or problems.
Revising involves rethinking your ideas, refining your arguments, reorganizing paragraphs, and rewording sentences. You may need to develop your ideas in more detail, give more evidence to support your claims, or delete material that is unnecessary.
Read your paper out loud. This sometimes makes it easier to identify writing that is awkward or unclear.
Have somebody else read the paper and tell you if there's anything that's unclear or confusing.