Using a blanket as a saddle pad?

I use to have a horse book that showed how to use a simple wool blanket as a half-sheet saddle pad. I think that's what it's called.

Anyone know how to do this? I'd like to give it a shot. I'm planning on decorating a red wool blanket and use it for Christmas photos with my boy Murray.

I'm not sure how to do it, but is it for a western saddle?

Do you mean something like this?
Rambo Newmarket Quarter Sheet - Dover Saddlery.

I've never heard of that, I think for Christmas pictures it'd be cute though (like the one Appy posted).