A lesser used lens

I have a 80 - 400mm lens that I struggle with. It is an excellent range for wildlife, but my frequency of well focussed photos is very small. Yet, like the game of golf, sometimes I hit an excellent drive and I keep coming back for more. I probably need to be a bit more scientific about its use to determine the best and worst places to use it - plus learn to either use the tripod/monopod with it or some other means to better stabilize myself.
Here's a shot that came out quite well - a rufuous hummingbird sitting in our willow tree. Guess I'll try the lens again...