Well, the method described by the OP is an attempt to equalize all exposures made during a session. A similar method is to take an incident light meter reading, which will help you "peg the high tones" and will allow the shadows to fall where they may...
Using the described method will eliminate shot-to-shot variations on sequentially-made photos, which can actually be desirable...many times it is best to get the highlight exposure "nailed" or as I call it, "pegged", and then disregard the meter's variations caused by large expanses of background which is relatively unimportant.
One issue about metering a lighter tone, like a Caucasian palm and then opening up one f/stop; that makes perfect sense if your meter is dumb and color-blind: if you have a Nikon camera that has color-aware light metering, it can tell, by color analysis of the red,green,and blue values, what the actual color of the object being metered actually is, so it's not necessary to open up one stop. For the majority of other cameras, opening up one f/stop or a little bit more, will ensure that Caucasian skin is rendered about the right brightness value in the final shots.
One place where the OP's metering method does work splendidly is when photographing a person in front of a dark background, like a hedge or treeline. A person standing in front of dark trees or hedges when using centertweighted or "dumb matrix" metering will often require an exposure that is around 1 and 2/3 f/stops darker than what the light meter indicates, to avoid over-exposing the person. So, let's say you want to shoot a family group or individual portrait session using a dark, shaded shrub hedge or bunch of dark foliage as your background...as you zoom in and out, including more or less person and more or less background, the exposures will yo-yo all over the place, when what you REALLY WANT is a good,steady exposure that has been "pegged" for the brightest highlight values on the person's skin...so, in front of a dark backdrop, a shutter speed faster than the meter indicates is needed, faster by around by 1 to 1 and 2/3 or even 2 full f/stops' worth of exposure,is often needed to get the skin tones pegged.
So, yes, the method the OP asks about is a good method. One caveat to keep in mind: using Manual exposure mode, a variable aperture zoom lens will lose aperture value as it is zoomed out...the method of metering the OP asked about works best with prime lenses or fixed maximum aperture zoom lenses.