D F Cardwell did an article here on APUG way back when that had a big effect on how I thought about metering, developing, and curves. He pegged his curves to the mid-tone in the scene, the most important area to him, and most portraitists, and street shooters, and a few others, rather than to the toe which is more important to Zoners, West Coasters, and a great many landscapers.

That article laid the foundation that Dunn & Wakefield's Exposure Manual built upon later.

In the comments to that article you can see several participants asking for un-slid curves. These participants are, IMO, essentially asking for help to square DF's ideas with their reality.

http://www.apug.org/forums/forum216/...-negative.html

One of the participants in that discussion 2F/2F, in this thread http://www.apug.org/forums/forum48/9...after-all.html , suggested adjusting the orientation of the incident meter head, rather than keeping the head pointed at the camera. At that point in time I was really having a tough time wrapping my head around that thought. It took a couple years for that to really settle in. Again it was Dunn & Wakefield's Exposure Manual built upon that later.

Once understood the utility of both of those concepts are really easy to use, very practical, and truly useful in making printing easier and more standard in relation to the original intent when shot.