Yo Lo.
I've been a bartender all over Europe for some years now, so maybe it
doesn't really count, but its - at least to my experience - a very good idea
to offer a nights work for free. If your really good that should do it.
But... 90f being a good bartender is about how you appear to "the general
puplic". Sell yourself and you will sell cocktails like anybody else in the
bar.