I always wear a dress when driving, but I see a lot of folks in dress slacks and blouses. My method is that for Western/classic - cowboy type wear, including a cowboy hat. Western blouses, and skirts, etc. Country is summery type clothing, skirts and blouses. I haven't found any hats that I think I look OK in, so no hat yet. Open I go a bit fancier - formal dresses, at least longer gowns. If it's evening, we glitz it up more. Nationals, pull out all the stops at all levels. Lots of bling, brighter colors so you don't get lost in the crowd