1. Don't wear jeans. Khaki pants are good. Dressing up shows that you are serious about being a professional for that company. Khakis won't get you hired, but jeans may cost you an interview.
2. Focus on how your job history shows that you are a reliable hard worker who will show up every day without drama.
3. Don't mention personal stuff like stories of past behavior or really needing a job - That doesn't matter to a hiring manager.
4. If you have negative history (criminal record, have been fired) be up front, assure them that it is all behind you, and then talk about #2 again, stay focused on the job and the future.