The max levels of the various species and the TR and weight ranges can be found in the Tips and Tricks section of this thread.
Most of the animals you harvest will be on the lower end of that spread as opposed to the higher number so the higher that lower number is the better. The weight ranges shown in tracks can be helpful in identifiying potential diamond quality animals. Your binos have x-ray vision, just be careful because you might hit the hill or tree or rock that the binos illuminated the animal through. Best thing is to what you've been doing except to look around before you pull the trigger. Mostly it's blind luck as they don't vocal much and depending upoon the species, diamonds can be loners.
