RE: which one to use: custom-set-variables, customize-set-variable, or customize-set-value?

[Drew Adams]

> > As I said, you can certainly do as you suggest.  My suggestion is
> > to clearly show in your init file how you are setting the value.
> > Including for different Emacs versions - so you are aware of such
> > changes when you read your code later.  But it's just a suggestion.
> 
> Here I was trying to make a case for some kind of "generic setter"
> which knows what the right thing is. Of course, such a generic setter
> wouldn't be half as valuable without a context. I wouldn't do it in
> my init file as of now, where it's not "usual".

BTW, maybe I should also have made clear that I think the best
practice, in general, is to use the Customize UI and let it
manage user options and faces, and to force it to do so in a
separate `custom-file' and not in the init file.

While one can call Customize functions (`customize-set-variable')
from Lisp code, my advice is to save that for commands you write
that dynamically manipulate (set and possibly save) options and
faces - as opposed to using such functions in an init file.

(Just one opinion.)