You've been invited to attend a medieval wedding and would like to dress up in a period costume, but you're at a loss of what to choose. Before you run out and purchase anything, you should first find out if the wedding is going to be a strictly peasant style medieval wedding or is the couple focusing on a wedding that is more suited to high nobles, lords and kings. Showing up in peasant garb when everyone else is in rich-looking outfits would certainly be awkward.
A lot of couples will put together a wedding combining the two social classes. They may have a simple wedding ceremony outside in nature (as the villagers and local farmers would do) and then move on to a medieval feast in a hall decorated to look like a banquet held in a castle. In this case, you could wear a costume that falls somewhat between the two classes, perhaps selecting the attire appropriate for well-to-do merchants, lesser nobles, royal knights, or a lady-in-waiting.
On the other hand, the couple may elect to have an elaborate church wedding and then have their reception at some outdoor venue, such as a park or local gardens. If such is the case, you need to keep in mind that royalty did not "party in the park" when it came to such an important celebration. Dressing down would be more appropriate choosing attire more fitting to the lower classes such as a serving wench, a lesser knight, a monk and a villager.
Just like today's modern world, clothing styles changed rapidly with each generation. Be that as it may, there are still some common elements through most of the styles. Men and women often had certain items of clothing that were worn by both genders.
The fabric used for medieval clothing was heavier than it is today. If you plan on sewing your own costumes, using upholstery fabrics would be best. Keep in mind that pastel colors were nonexistent at this time. The colors should be vibrant, rich and deep. Choose fabrics that contain deep blues, emerald or forest green, deep reds and burgundies, ocher, bright yellows and chocolate browns.
The kirtle (undergarment) can be of a lighter weight material if you wish (if it is going to be entirely covered), but your cotehardie (the main outer garment) should be "rich" looking. Choose a suitable fabric for this such as velvet, brocade or damask. These garments were worn by both men and woman, with the man's being shorter in length.
Take care in choosing the fabric pattern. Medieval clothing did not contain stripes, polka dots or small patterns. The occasional outfit may have had large diamond shapes, but this was rare.
By the fourteenth century buttons began to make an appearance and were created using small balls of cloth which were then stuffed with wool. Before buttons were invented, people used leather laces, ribbons and other such ties to secure clothing.
Peasants, villagers and other workers didn't have the money or access to the fine, rich materials that the nobles wore. Instead, their clothing consisted of rough wool and linen garments. If you elect to wear peasant garb, choose attire made from linen, cotton or other such materials so you will remain comfortable.
It is usually more feasible and affordable to rent a medieval costume. However, the downside is that unless you live in a large city that has a variety of local costume rental shops or a professional theatre from which you may be able to buy or rent your attire, your costume selection may be limited. Buying a medieval costume online or sewing your own would probably be a better choice.