If I left you a message: please answer on your talk page. I will keep an eye on it so generally I do not need a {{talkback}} notice, although you might want to use one to inform me if you reply with a significant delay or if you want me to reply rapidly.
If you leave me a message: I will answer on my talk page, so please add it to your watchlist or otherwise keep an eye on it. I may post a {{talkback}} notice on your talk page, but only if I think you haven't seen my reply.