I just take a picture of what i have at the moment. For example when i need a long lens and i didnt have the 70-300 id just take the 135. If not that id take the 50L. Look, i better go home with a picture which i have to crop instead of no picture to not even look at it.
Additionally i just run to be closer. I always run if i want to capture a moment, because a second later it might be to late.
I remember last week i saw a very unique scene and it looked just great. I would've needed the 135L or a 85mm lens, but i just had the 50L on. So i ran 20ft closer to take the picture. Not as close as with a 135L but i got the shot.
Just shoot with what you have and if you can, walk towards your subject..



