One of the things that helped me to try improving (not much success anyway, but that's fully my own lack of any kind of "artistic eye") was by using the "wrong" focal lens for wildlife. In my last trip, I forced myself to use 800mm to shoot small and big. With the small subjects, no problem, but with the big ones... OMG... "nothing fits!"... then, I tried to frame different portions, angles, positions... and somehow I came back home with maybe a handful of closely framed animals that didn't follow "the rules" yet, I was kind of proud of the results.