Is there any kind of rule-of-thumb for yeast selection when coming up with a recipe? For instance, if you make a typical heffeweizen, the yeast is profoundly front-and-center. You can't NOT notice it. A good many of the IPAs I've had though, the yeast is more like a bass player. You can tell it's there, but with everything else going on, it's hard to notice unless it's not there.
Do you kind of just settle on a yeast you like, or are you constantly experimenting?