I think not there is a smarter way as NOT forget your Teleporterstone(s).
But maybe you can make a "note"?
I've had this problem also some years ago starting with my first characters ...
Now I mostly write down the exact place where I place a Teleporterstone, so if I drop and use the other stone somewhere and later on discover I've NO Teleporterstone with me ... my "note" I maked can help me to find at least 1 of the 2 stones so I can fast travel and put the forgotten stone back in my inventory
.
If I "think" to know where I forgot one of my stones, I travel to that place and run around while I press the ALT key so all usable items lying around are lighten up whole the time
!
