There are all manner of accessories you can add to your costume to flesh it out, make it more accurate, or just more ornate. Below are a few ideas.

Pomanders
For the high middle class and nobility, pomanders were lovely. You can make your own pomander with an orange or tangerine taking an awl and poking holes in the orange, and placing whole cloves in the holes. You can glue ribbon around the whole orange, and leave a length of ribbon to attach it to your belt. You can also skip the glue and poke holes through the ribbon into the fruit and secure it to the fruit with the cloves. Hang this in a cool and very dry place for about a week, and it will be ready. Don't leave it in your bathroom or kitchen, as it will mold from all the moisture. You can also purchase a metal pomander from A Wardrobe in Time. Made of gold or silver metal, this is basically a ball with holes on a length of ribbon or chain. Inside the ball, you can put a number of things. Cloth soaked with essential oils, cloves, potpourri and sachets are all perfect to put inside the pomander. Ladies, and even some gentlemen, carried these on their person because back in the 16th century, both city streets, and city people tended to smell pretty nasty.

Fans
I cannot even express to you how nice it is to have a fan at Faire. They're lovely, and when it gets hot, they are a lifesaver. Peasant women can have fans woven of wicker, leaves or straw. Middle class and noblewomen have a much broader spectrum to choose from. Fabric fans, feather fans, fans of carved wood...there are a multitude of lovely fans to choose from. Please avoid plastic fans, or fans with decidedly modern prints and patterns on them. Fans can be carried in a basket, attached with ribbon to your belt, or carried in a pouch.

Eating Utensils
Some peasants carried their feast gear with them. Even bowls. Peasants rarely had flatware. You'd likely have a knife, though. However, only the upper classes would have forks or spoons just for their own usage. Peasants might have a rough wooden soup spoon.

Drinking Utensils
Many people carried their drinking utensils with them, as well. Generally carried in a basket, or attached to one's belt with ribbon, rope or cord, peasants might have a battered metal or wood tankard, while the upper classes would have more ornate tankards, or pewter goblets. The Pillaged Village and Fellowship Foundry sell lovely drinking utensils. You can also scope out your local thrift and antique stores. The metal tankards with the see-through bottoms aren't very period, but they're good enough, and you can usually get a deal on them.

Pouches
Easy to sew, and easy to buy, you'll want some pouches to carry your things. ID, Participant's Card, makeup, cigarettes, medication, anything you need on your person at all times. Make sure you attach these securely to your belt.

Jewelry
Thrift stores, antique stores and Goodwill stores are great places to hunt for jewelry. It doesn't need to be 100% accurate. It just needs to look accurate enough. Avoid plastic beads, and things constructed entirely of rhinestones. Look for things that look "vintage". A lot of jewelry that's technically "Victorian" in theme works great for fair. Stones set in metal are wonderful. Keep in mind that prong settings, which as so common now, did not exist. Stones were cut to fit metal settings, or glued into them. Flashy stones in gold tone filigree settings are perfect. Pierced earrings are not period, however, do not hestitate to wear them, as clip earrings are easily lost and can be rather painful. Rings, necklaces and pins are all wonderful. You can even use necklaces to string across your bodice. Keep in mind that the only jewelry peasant women would have would be very humble. Made of ribbon, bone, leather or clay, peasant women nearly never had jewelry, but this is a Faire, and likely, they'd want to dress up to the best of their ability.

Trade or Leisure Items
Women, feel free to carry wooden embroidery hoops, and sit down to work under a tree if you wish. Carry your washing, mending, sewing, anything that looks homey and period. Items of your trade are great, as well. Belaying pins, wooden thread spools, tools and anything else can make charming additions to your costume.