I’ve used a mirror. Then I started mounting it on a clear resin chair someone bought me off my wishlist. Or you could get one of these... which a member also bought me off my wishlist. But I do recommend the weights that are to be used inside, as it does want to slide a bit if you don’t have it on a floor or something the foam pads can grip to.
TOM v2 "The Other Man" Suction Dildo Mount
Amazon product ASIN B00A52GCJG