Just as I do it.Wear a short black skirt and pee down your legs in your panties.All what you will have are wet panties and legs.Your panties will soon dry in about two hours.As for the smell, it is usually a vague faint odour and no body will ever notice or imagine that you have peed yourself.From my experience,the faint pee scent of your legs will gradually fade in about an hour.No one will ever notice unless he smells your legs deeply and this will never happen under normal circumstances
There are a couple of ways. You can keep a "special" pair of panties and/or shorts and wet them in the shower. Rinse and wring them out while after you pee in them, then hide them in your room to dry in between times. Or you can make a diaper out of a towel, pee yourself in the shower, then rinse and wring it and put it with the other towels.