Interesting ideas in this thread so far. Keep 'em coming.
SNAP SHOT MODE
Thinking about it, I actually use my M6 in two entirely different ways.
A considered slow way with large apertures, careful focusing and exposure, often for available light portraits when indoors.
I also enjoy the freedom of snap shooting outdoors using hyperfocal and F8 or smaller. Set Hyperfocal distance for the aperture desired ...see link below
http://www.dofmaster.com/hyperfocal.html
Next take an exposure reading at that aperture to get the shutter speed correctly set then just snap away, within the range allowed as indicated on the lens.
I will often set the camera lens for HYPERFOCAL at one stop larger than being used e.g. set lens for Hyperfocal at F8 when actually using F16 to be more sure that all will be in focus.
This is where an M7's AV mode would come in handy for light changes, if I owned one!
HAND METERING
I actually use my hand a lot with the M6 to resolve any metering challenges, normally adding one stop to move the reading of my palm to a mid grey tone.
I try to keep in mind Sunny F16 when reading a scene overall and if the camera meter reading differs greatly from that then the hand comes into play. Examples where this is often the case include backlighting, or mixed/non mid grey tones like a beach.
http://www.fredparker.com/ultexp1.htm
http://en.wikipedia.org/wiki/Sunny_16
If a hand reading doesn't agree with metering the overall scene then I generally go with the hand.
I find the hand method very reliable, providing I make sure the hand is in the same light as my subject. Not much good metering your hand, whilst sitting indoors taking a picture of your garden through the window! Also remember to point the camera slightly downwards to avoid too much sky influencing exposure readings.
Naturally, always just take a snap if time dictates that it is that or lose the moment.
B+W OVEREXPOSE SLIGHTLY
Like Al Kaplan suggested when using 400 B+W C41 film, I tend to set M camera at 200 plus two clicks (asa250?) to slightly overexpose. For colour film, I normally set exactly as recommended by the film makers.
I like to use an orange or yellow filter for B+W to improve clouds/sky.
PS I know that for many of you gurus this is all very basic stuff but hey...
someone may find something useful or new in the above.