An awesome trick I learned.

Put your toy in a condom. Put a fair amount of lube inside the condom, and a bit on the outside. Poke a few small holes near the end of the condom, with a pin. I then twist the base of the condom a few times, and stretch it over the k-tab, so at least as much lube can't leak out the base. The lube will slowly leak out the holes you poked, getting way up in there good, with less waste, and the condom ends up skin tight to the toy, so you don't even really notice it's on there. If you absolutely have to, you can eventually turn the condom inside out, and use it some more, with the super lubed side out, or take it off, since there is now so much lube inside. Enjoy!