What can I do to help make a successful disability claim?

Find a QME. A qualified medical examiner. Sometimes you may need an attorney too.
Be honest. If you have real injury, and is seeing a trustworthy physician, with documented medical findings, then he should have no trouble getting a successful disability claim. Problems occur when there are totally subjective complaints with no objective findings, discrepancies in the history or contradictory multiple examinations by different providers, dr. Shopping, etc.