Putting a texture on a lamp will look very 2D no matter what you do, but to add distortion to the globs you already have, you can use a panning noise normal map, multiplied down to .02, masked to only RG channels, then added to a basic texture coordinate, and plugged into the UVs of your texture. The normal map will displace the globs on your lava lamp and give it a really neat distortion effect. It’s one VFX trick everybody needs to know. If you use this same technique on particles, then have the particles float around inside the lava lamp and just use a glass material on the outside, you can effectively make a 3D-looking lava lamp. Depending on how far you want to take this, you can use lit, masked, subsurface models with actual placed lights and have the individual globs cast a shadow.
The only way to go better than this is with volumetric decals. But those are highly expensive and experimental, no game I know of uses them.