There are many different types of bedding for horses, including wood shavings. Wood shavings absorb moisture well, which keeps the smell of urine manageable. They are cheap and easily available at lumberyards and feed stores. What's more, they're easy to keep clean. Mucking out a stall with shavings in it can be done in 15 minutes.
Turn the horse out to pasture or put it in cross ties before you begin mucking the stall. Having the horse out of the way will help you focus on the task at hand.
Position your wheelbarrow as close to the door of the stall as you can for ease in depositing soiled shavings.
Muck out the manure first. Use a shovel or pitchfork to scoop out all manure into your manure bucket. A shovel may be more useful for closely piled manure, but you may want a pitchfork when the manure is spread out. Sift through the bedding with the pitchfork to catch any stray pieces of manure.
Muck out the urine. Many horses urinate in one spot, making a wet, significantly darker spot in the shavings that is easy to see. Use your pitchfork to scoop all soiled bedding into your wheelbarrow. If an area looks like it might be wet or soiled, remove it.
Dump the soiled shavings you've placed in the wheelbarrow onto the manure pile outside the stable. If you are running your own barn, try to place the manure pile far away from where a horse might have cause to be near it, such as behind the barn.
Sweep out the wheelbarrow and place fresh bedding in the stall. Sweep the aisle in front of the stall and then bring your horse back inside.
Muck your horse's stall at least once a day, but preferably twice a day. Every month or so, deep-clean your horse's stall: strip out all the bedding and wash the floor underneath with a disinfectant such as bleach and water.