I guestimate yards with the assumption my accuracy is within the few inches difference between yards and meters, then try to avoid a wide open aperture! I did finally acquire one of those shoe mount rangefinders, but that's yet another fiddly thing to mess with. (I wanted one of the Voigtländer jobbies, but they seem to sell for about twice what I was willing to pay.) I've screwed up the distance occasionally, but not often enough to get excited about it.