"Sorry, I am busy now." - There isn't anything wrong with this phrase but do you realize the word busy is used too frequently in your daily life? Sometimes I am wondering how busy can a person be??? Somehow to me, it appears to be a crap excuse. It is just a matter of whether you actually make the effort to do it or just an excuse not to do it or avoid or whatsoever reason.

P/S. I hate the word - Sorry. Use it on me when necessary, don't overuse if not that's the end.