Join Date: Aug 2009
Location: New South Wales, Australia
Does the saddle fit? What is your horse's back like?
I guess the first step is to identify the problem. When the saddle slips is the girth really loose or still tight? If it's loose it's probably your horse "blowing out".
If it's still pretty firm you'll need to look at your horse's back and the saddle. A saddle that doesn't fit right will slip, in which case the solution will be to either get your saddle fitted or get a new saddle.
If the saddle fits well then you need to consider your horse's back. If it's very flat and "rounded" with little or no wither then sometimes you just can't get a saddle to stay put. Then you might start looking at saddle pads designed for horses specifically like that or other solutions.
Another thing is that when you mount up don't pull yourself up, spring from your foot. Don't go straight up and then throw your leg over either. Kind of spring up and across the back, don't pull yourself up by the saddle, rest one hand the horse's mane and the other over the other side of the saddle where you can kind of "press down" for grip.