I worked for USAirways for 16 years and I am now happily retired. When I began my career all non-revs were required to wear a coat and tie, no jeans were allowed in either coach or business nor were tennis shoes allowed. The policy changed for coach non-revs but remained unchanged for business class non-revs though the tie requirement was waived. I have done my share of non-reving on OA and I have always dressed in a coat and tie. I have been upgraded on OA (especially AA in Miami) without asking though I never ask the gate agents the reason. Dressing nicely is painless and has its rewards.