My ears are insensitive, my mouth unable to wound.
I wouldn't allow anyone to annoy me, just because their way of doing things is different from mine. Tell him/her your way of doing (whatever you're doing) is different because (discribe why), but you'll be glad to consider his/hers. Smile, thank him/her, go about your business.
Say to yourself: I know what to say, and I say it. I know what to do, and I do it.
Because you DO, of course, know what to say and do. Don't allow this person to make you feel any different. What do you care what someone else says, really.