hello my friend,
you either have wit or you don't...wit, like humor, is something that is not learned...acquired perhaps, but only to an extend and a very small degree.
all is not lost though...you can always learn a skill etc. to set you apart from your competition.
I would suggest you'd stop trying to develop things like wit and smooth talking because it is simply not possible. Not only that, but people will be able to tell you're trying too hard, and that my friend, is the equvilant of being an idiot....if not worse!!!
It is a mindset and lifestyle that you simply have or you don't
not all of us can be smooth
best wishes.