Key words to say
Instead of saying "Im just joking." I will say something ridiculous in its place and keep talking like nothing ridiculous was said. So I will say "no no no brother Im just slappin yo granny." or "Im just beheadin your kittens dude" its interesting to see what ridiculous things you can say casually and how you wont even get a reaction if you say it with confidence.
That's funny, I think I'll try that
I told one guy at work "im just spittin in yer coffee"