There's a "new to me" spray out there called Grippy Spray. You spray it on the back of your ruler - it dries almost instantly - and it really holds your ruler. It doesn't have an awful spray and I just poke my ruler down into my waste can and spray. It last quite awhile too. It works great on those small templates and small rulers that just won't hold still.
Fabric Obsession in Medina, OH carries it....I don't see it on the website but if you give them a call they ship anything.
https://www.fabricobsession.com