You don't need "horough experimentation or careful analysis". Just keep free swap space below few hundred megabytes but above zero.

"Keep swap space below few hundred megabytes but above zero" is a good example of a rule of thumb.

"Make the swap large enough to keep all inactive anonymous pages after the workload has stabilized, but not too large to cause swap thrashing and a delayed OOM kill if a fast memory leak happens" is not.