How can we optimize fluid simulations in Houdini to achieve both realism and efficiency? Whether it's refining particle counts, adjusting solver settings, or leveraging caching techniques, what are some strategies and best practices for achieving fast yet visually stunning fluid simulations in Houdini?

That's a very broad question. I'd suggest you get to the Learning section of the SideFx site and look for some tutorials to start. Definitely supplement with the docs and finally ask more direct questions in the forum.

Cheers,