>>4391284Go a solid half-dozen outings doing that at least I reckon. 85mm sounds like a good FL to use for isolating subjects or compressing backgrounds just a little, without going all uncanny on the subject distance. Not gonna have the ability to do environmental inclusions with your subjects, but that means you'll think more about the subject itself, right? That would be the point after all.
As some anons have pointed out 35mm being another common FL to use for this, that would force them to think about environments and subject's position relative to that. Using a fisheye would force you to be artistic and look at the bigger picture so-to-speak. etc. etc.