DJ wrote:I prefer Fuji Velvia 50 which I generally assume to have about 4-4.5 stops of range
I would disagree with that estimation of range for Velvia 50. I used to expect that from Velvia 100 but found that I was still getting blocked shadows or blown highlights. Since I started limiting Velvia 100 to 4 stops my results have been much more predictable. Although I have never actually used Velvia 50, my feeling is that, if you limited the expectation to between 3 and 3 1/2 stops, you will stand a better chance of "perfection"
DJ wrote:... and I rate it as ISO 40 on my meter.
Now this is something I never understand; why change the rating on a film ? Surely, what would be better is to understand how much of the range of the film is above and how much below the "standard" exposure instead of just cutting the range in half ?
For example, my Nikon D100 seemed to meter for 1 1/2 stops over and 4 1/2 stops under its measured exposure before blowing and blocking respectively. Come to think of it, that used to force us to deliberately under-expose by 0.7 to 1 stop; so I guess adjusting the ISO rating on film could achieve the same kind of result.
DJ wrote:I put my meter into EV mode, and look around my scene, I find the EV of the highlight area, and I find the EV of the shadow area to find out what range I must work with. I'll then use ND filters to get these within 4.5 stops of each other if at all possible. I then look around and find something in the scene with a reading just below the mid-point of that, and use that for my final metering. For example, if my highlight is EV 9.5, and my shadow area is EV 5, I'll look for something at EV 7 or thereabouts. When I'm done with the filtering etc, I'll switch the meter back to aperture mode, set my aperture, and take a reading from my known metering point. Then add on any compensation for reciprocity failure or bellows compensation, and you have your exposure time.
Now this is something that I (sort of) do; except that I simply take (for Velvia 100) the shadow reading and then add two stops to it; sort of the equivalent of placing that reading in zone 3 for B&W work. I then meter for the highlights to see what I get that is over the "zone 5" reading and if it exceeds 2EV over, I will try and use a grad ND; if the over-range highlights are in the middle of the shot and can't be filtered, I will either abandon the shot until a softer light or take more than one shot to accomodate the range, mixing them together in Photoshop. N.B. I do not use the HDR gizmo in Photoshop, instead I manually copy correctly exposed Highlight/shadow areas into the "other" picture and blend them together
subtly 
So Tom, my 2¢ worth of advice is not to take your reading from a "midpoint" but, as DJ suggests, to take it to be a known difference from either a shadow or highlight point, depending on the film range.
e.g.
You are taking a scene in which you have a clearly separable are like the sky over a relatively straight horizon.
The darkest part in which you want detail reads EV7 therefore your exposure will be whatever combination of speed and f/stop gives you EV9.
Then, and only then, do you meter for the brightest part of the sky which, for the sake of the example given gives you EV13; therefore you will need a 0.6 ND grad, but this has no bearing at all on the already decided exposure.
Now, does that clarify or confuse ?
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Left hand end is "0" and right hand end is "10"
. Well i'm probably the second to last person to ask, but here goes. Meter from a midtone area where the light is catching it, and not from a shaded area (sorry if that one was obvious). Your eyes will learn with practice, as are mine still; a medium grass as Lynn said, the red brick of a building etc. Are you familiar with 'reciprocity failure'?.