You mentioned the first thing that I get commented on when I gift a bar of my soap (I do not sell). Thats the smell. It never seems to matter what the packaging is, what oils I have used, or the colors\swirls - they all just smell it and state their opinion.
When I first started buying soap (before I learnt how to make it), I would do the same thing.... smell and maybe color would come into consideration. I did at one point look for the goats milk but it was never a deal breaker if it was not in the bar.
So make your booth as invitiing as possible... make sure your soaps smell good and then as the consumers use them they will come back for more. Do you have a brochure to hand out extolling the virtures of your soap. I wonder if this would be a good idea as you seem to have fairly heavy competition at this craft show.