Incense can be a great way to make your costumes smell better without wasing them. I recomend buying a strong incense in a scent that you like. Burn the incense in a safe container on the floor and waft the costume in the smoke. Try to absorb as much smoke into the costume as you can, as this will be where the scent as coming from. Make sure that you are very careful with this as it is lit incense and it has the potential to burn a hole in you costume or even worse cause a fire. Always use extreme caution when wafting and never leave the incense unsupervised especially if you have infants or animals nearby
Perfume Oils
Perfume oils are great because they can potentially last longer than a water or alcohol based perfume. There are many different scents that can be purchased from almost anywhere. My favorite scents are the ones that come from India especially since they usually come with a cute little bottle too. Simply apply the oil onto your skin but... the trick to making it last longer is not to rub it, allow it to naturally dry and absorb into the skin. Did you know rubing the oils will break down the molecular structure causing the scent to fade.
Deoderizing
Although I'm sure most of you out there do deoderize I have to mention this because I have too often come across a dancer who has not deoderized before dancing. They dance beautifully when their onstge and then they come off the stage and dance around the room often with arms raised and spoil the performance because the audience can't enjoy it well their holding their breath. Even if you've deoderized in the morning, always do it again before a performance. I would be mortified if I were one of those dancers. Also with newer products like febreeze you can now easily deoderize your costumes. I often spray febreeze on mine after a performance.
Perfumes
Any perfume that you like will work well but I find muskier scents are often good for dancing, they have that exotic Middle Eastern scent to them. I often like to use Shalimar or Opium, those are my favorites for dancing because there beautiful yet strong enough to cover the smell of perspiration. I find light, flowery scents often fade to quickly.