Horse and rider fancy dress lends itself to all manner of possibilities, as there is nothing better than having a real horse to dress up with. Some costumes require a lot more preparation than others. In addition to the suggestions offered here, if you put your mind to it, you are bound to come up with myriad fun dress-up possibilities.
If you like pretty colours and flowing robes, dressing yourself and your horse up as Arabians may be the perfect fancy dress idea. Sew or tape fancy braiding or sewing notions onto the bridle, with fringes or pom-poms handing down from them. Place a richly decorated flowing sheet with gold or silver accents over the saddle. Dress yourself in flowing robes also made from fabric that has gold or silver highlights in it. Cover your head with a different coloured fabric and tie it on with a gold headband. Wear sandals on your feet.
Use poster paints to create circles around your horse's eyes and make hand prints on his body. You can even paint patches or spots on him to make him look like a paint or Appaloosa. Braid feathers into his mane. Use a rope bridle and rawhide reins and a brightly coloured folded blanket instead of a saddle. Paint war paint onto your face and wear feathers in your hair. Dress in a fringed skirt and blouse, or, for a boy or man, fringed long trousers and no shirt. Moccasins will complete the outfit.
Cowboy or cowgirl
Everyone loves to dress up as a cowboy, and what better time to do it than when you are on a real horse. A tasselled checkered shirt, bright kerchief, jeans and chaps or a fringed skirt, boots, spurs and a cowboy hat are all that are needed for the rider. Use a Western saddle and tie a dally of rope onto it and a bedroll behind the seat. Make a Western bridle with a Western bit, no noseband or browband and plaited reins. A toy gun and gunbelt or scabbard and rifle will complete the outfit.
This is particularly effective if you have a heavyset horse, like the old warhorses used to carry knights with their heavy metal armour. Use satin or shiny fabric on top of your saddle blanket and sew arrow-shaped tabs hanging down from it. Add a length of the same fabric with the same tabs sewn hanging from it to go around the horse's rump and chest, and even dress up your reins with it. Use cardboard, aluminium foil and glue to fashion a helmet and breastplate, which you can wear over grey or brown trousers, a white shirt and foil-covered boots.