I freely admit that of all the punctuation marks, commas cause me the most confusion. I definitely suffer with comma-itis—using them far too much.
It’s not just me who has problems, for as Oscar Wilde said:
“I was working on the proof of one of my poems all the morning and took out a comma…In the afternoon–well, I put it back again.”
Anyhow, I came across this erudite article about how to use commas without looking like an idiot.