Two techniques in eleven minutes. The first is the laser visualiser: a mirror fixed to a vibrating surface, a laser aimed at it, and the reflection thrown onto a wall. Because the surface deforms differently at each frequency, the reflected beam traces a different figure each time, and playing two tones at once gives compound patterns. It projects large, which a plate never does.
The second is the Chladni bucket — a stretched plastic membrane standing in for a metal plate, driven the same way, with powder settling into the low-motion regions. He notes the traditional plates were originally excited with a violin bow.
Both are cheap, and the laser one in particular is worth knowing about if you are trying to get cymatic imagery in front of an audience rather than a camera. The explanation of why the reflection changes shape is unusually clear.