I do one or more of the following :
Move to another location where the conditions are the same or similar to what they were when the fish were biting.
Change tactics & methods & even baits ... when those same/similar conditions can't be found.
Fish for another species that's more inclined to bite under the prevailing conditions.
Use this method to try and coax a few more fish to bite:
Crappie Pappy Article
They don't ALL quit biting, all over the lake, at the same time, so when the spot I'm fishing stops producing ... I consider the possible reasons & change location, tactics, and/or bait, and start hunting for them again. I also don't go looking for "obvious" spots, or community honey holes, but look for spots that may not be well known. How much time I'll devote to "searching" for them depends on how many I've already caught, or how long I've already spent on the water. Most lakes that I fish are a 1.5 to 2hr drive each way, so that can be a deciding factor in how long I stay on the hunt.
... cp