Depending on the size of the toy in question, either zip lock bags or those luggage vacuum bags. You don’t have to vacuum pack your toys though!
We always seem to end up with multiple wash bags anyway, so one more for the toys isn’t a problem! Makes use of some of those that came as Christmas gift sets.
If looking for small/discreet/packable Tenga SVR vibrating cock ring and We-Vibe Tango X bullet vibrator. Both pack a good amount of punch in a small package.