When we think of fall, two things come to mind right away: harvest and fall leaves. Center your fall theme wedding on these elements. It can even be metaphorical: love is the harvest shared between two people on your wedding day. For the ceremony, choose colors you'd find along a Maine highway in October: brilliant reds, browns, golds and eggplant. Use dried flower bouquets accented with some fresh flowers of the season. Raffia can be tied around bouquets and other decorations for a natural, harvest look.
A wonderful place to hold rustic fall weddings is at an actual farm. A converted barn could be an added bonus room. If you know someone in your family who has a hobby farm, ask if they would be willing to donate it for the occasion. Or, do a little research. Depending on where you live, there may be farms that can be rented for just such an occasion.
If you can't have your reception at a farm, choose a venue with a natural feel. It would be nice if it is surrounded by trees and nature, to remind you and your guests of the harvest and the colorful leaves. A vineyard, a golf course, or an arboretum, would be a nice choice.
Decorations should be kept as natural as possible. For centerpieces, make use of Mother Nature's offerings by creating cornucopias of gourds, squashes, cranberries, dried flowers, herbs and dried leaves. Or, fill a glass hurricane lamp with cranberries, and put a candle on top. Consider filling large glass containers with apples, and scatter them throughout the reception. Or, consider carving small pumpkins in floral patterns and placing tea-lights inside. White Christmas lights may be accented with tulle in fall colors: deep purple, gold, red, etc.
Ceremonial music may include Celtic sounds or classical guitar. Consider a reading or poem that incorporates fall and harvest into the love that is shared between the bride and groom.
For dinner, selections of the season are a natural choice. Potatoes and squash, hearty salads with lots of greens and soups can be incorporated into the meal. Consider salmon or roasted chicken for a main course. The side dishes will likely be hearty, so keeping the main dish lighter is a good idea. Consider serving pumpkin pie, as well as wedding cake, for dessert. If you are having your fall theme wedding at a barn, you may set up bonfires outside for guests to share stories around, or make toasts.
You'll want to send your guests home with a favor to remind them of this special day. Again, think of the bounty of the season. A Ball jar filled with nuts and dried fruits may be a charmer. Wreath ornaments with the wedding details inscribed upon a ribbon would be a delightful favor. Or, a votive holder at each place setting, made of metal or pewter in the shape of a twig or leaf surrounding the candle holder could be taken home. You also might consider small sachets filled with autumn-scented potpourri.