I will provide a counterpoint to Mark and say that "one shot, one negative" certainly is something to strive for, not as the end result of personal photography, but as a way to free yourself from the drudgery and technicality of photography as art, this is specially relevant IMO with LF photographers, who seem to fall on an endless loop of testing, looking for the glass with perfect bokeh, the developer which will produce the best hghlights and the deepest shadows with detail, etc. This to me, more often than not denotes a lack of technical mastery that is getting in the way of making photographs.
People say or tell me "I hate testing", " I am a photographer, not a lab tech"...well yeah, I hate it too, but I do it so I know that when I press that shutter, I got all the information I want in that negative. This does not mean that I will not later on interpret the negative differently, and it has nothing to do with vision, it simply means that I am confident that I will get what I want and I can concentrate on the aesthetic and enjoyable part of photography more.
I remember before I learned the BTZS, I was adamant it was all too complicated, so I followed saint Ansel's teachings, well, let me tell you, photography for me was very stressful, I would do all those tests, miriads of 4x5 sheets with gray tones, I would go out and do all the spot metering, bellows calculations, filter factors, etc, etc, only to always have a small nagging doubt in my mind "will this negative come out ok?".... Since invariably some of them did not come out ok. Now, with the aid of the BTZS I know the negative will come out ok, I now concentrate on composition, placement and looking for better spots than I ever did with the ZS. Exposure calculation is only a matter of a couple of minutes and at this point I am certain the negative will not be underexposed, overdeveloped, undedeveloped, overexposed or whatever combination of errors that plague us.
I beleive this is what Francesco means by "one negative, one shot" and I agree with him completly. Lets remember, Weston did not have at his disposal all the new theories and ways to work and standarize exposure. AA was one of the few who had available to him a personal densitometer, now, we have more of these than we can shake a stick at.
In the end, the proof is in the pudding, and as such, there are times when all I do is measure the DR of my negative, look at my charts for exposure and contrast for that range, dial in the exposure in the plate maker, and it is done.....sometimes I have to make 2 or 3 more exposures to fine tune, but I dont anymore spend 5 or 6 hours fighting with a negative to get a print. Once again, knowing my materials has freed me to realize my vision, I might spend 5 or 6 hours changing what I saw, but I got it all in one shot.