I wanted to share this process for "aging" bones with you all, using Tim Murton's recipe. After acquiring your bones (buying them or digging them up from the local cemetery the ol' fashioned way) you may want to "age" them by adding color and dirt.
So, create a "bath" of 1/2 white glue and 1/2 water, then mix in a bit of yellow paint. Add just a touch of brown, like raw sienna, until you get a color you like. Get the bone thoroughly wet, allow the access to drip off and then roll the bone in a mix of dirt and dry moss.
Allow to dry and voila! Ready for your cemetery!