Whenever I attend the Texas Renaissance Festival or look up other festivals on the web or television, I'm always amazed by the clothing and costumes people wear. Of course, "Renaissance" is a term loosely used at many of these festivals (Exactly what do pirates have to do with the Renaissance period?), and that applies to the fashions at these events as well.
Most of the people I have seen in costumes at these types of events usually go for the traditional peasant outfit, which means men will usually be wearing a long shirt, doublet, possibly a jerkin, a codpiece, tights or baggy pants, and a pair of soft shoes and women will be dressed in a bodice, a blouse, maybe a corset, and a skirt. These clothes are usually dark in color (excepting the shirts, which are mostly white), and can easily be purchased online, in costume shops, or at festivals and faires.
A few people go all out with their costumes, particularly those hoping to portray royalty or warriors. Royal women usually have on lavish gowns with jewels and fancy crowns. Men usually have on fancier jerkins and doublets and some sort of weapon at their side. Those portraying knights will often wear polished armor and have weapons of varying size and shape. These costumes can be quite expensive.
Of course, there are also those who indulge in wearing a kilt, some sort of pirate costume, or costumes based on fantasy creatures like fairies, leprechauns, and goblins. You'll also find people dressed as gypsies, characters from the Robin Hood stories, or even wearing chain mail bikinis!
I think what it ultimately boils down to is what a person can afford and just how much (or how little) they want to wear. I have a personal friend who handmakes her own gowns (she's a seamstress by trade) and clothing for others as well. She does extremely detailed work, and I have a great deal of respect for her and those like her who make these types of costumes. I have another friend who prefers to keep things simple and wears a simple peasant gown.
Although I have never personally worn a Renaissance costume before, I have started considering either making my own or getting someone to make one for me. It really does add to the overall experience of a person at a festival or faire, and now that I've been attending and enjoying these types of events for three years now, I'm starting to get the Renaissance costuming bug.
If I ever do make or purchase a Renaissance costume, I'll be sure to post a photo or two here. For now, I'll include a few pics I've swiped off of the web.