I do beta-reading (basically proof-reading and checking for tone and consistency) for a couple web serials, and I like to joke that I take commas away from one author and give them to the other. But really, my poorly-kept secret is that I am much, much more strict with their comma use than my own.
I use so many more commas than I probably should, but I blame the Victorians. (I blame them for all of my writing’s perceived flaws. They can’t argue being my scapegoat, either, because they all died decades ago. Hah!) But despite not having too much of an effect on my writing, the editing’s been very educational. I’ve had to look up situations to know whether a comma is really necessary or not before adding or removing it and learned quite a lot about punctuation in general.
For example, the American standard is to put the closing comma inside the quote, before the attribution, and not after. Which personally I hate, especially when quoting text. You should put anything inside the quotes that wasn’t actually in the thing you’re quoting! It is, as Spock would say, highly illogical.