Hi. I tend to get a lot of bookings from wedding fayres. I always make sure there is a Catwalk on and do the models make up. It is much better for the (potential) client to see. I also make sure that I do the make up in full view of everyone, so they can see me working. This invites them top come over and feel more confident.
If you offer this free, then you dont pay for your stall ;-)
Hope this helps xx