How do you express your personality? Well, easy.... just be yourself. Find the salsa style that you like, that lets you have fun in the dance floor -- and your personality will naturally come out. I know it is very hard for beginners to 'cut-loose' and not worrying about doing the combination right, or for the ladies to make sure they are paying attention to the leader. But, even if you don't know a lot of combos, you can use your basic step and spice it up with your own style and personality. When your personality shows, (and hopefully is a fun one), more people are going to want to dance with you because it will seem more natural and fun.
And please for God sake... don't chew gum while you dance! Use breath mints instead... (Of course, you should brush your teeth before you go out to the club)