Ok, truth be told, I don't know the "true" definition of a trunk show, but I know what I've seen in my LYS. For a knitwear designer, they send a "trunk" with all of their made up designs, we sell some patterns, suggest some yarns. It allows for exposure of that particular designer and helps those shoppers who need to see the garment in the flesh. Certainly it works the same for bags, doesn't it?
One of the struggles of being a one woman show is how to continuously - yes continuously - market oneself to to ensure sufficient growth and customer base to sustain life. A home based business plateaus as any other business if one does not keep up with the marketing.
During the last 2 months of 2009, I had two trunk shows. One hosted by friends. One in my LYS. I have one more scheduled for February of 2010.
Consider this --- if hosting a trunk show in your abode - or the abode of a friend, it really is no different than a Pampered Chef party - or think Mary Kay. I know we've all been to or been invited to one of those! You simply invite a lot of people, serve some refreshments, tell a bit about yourself, display your goods, and take custom orders if you wish. There are a tools to help you facilitate this (Think Evite, Microsoft Word to create invoices...)
When hosting in a Yarn Shop or other brick and mortar establishment - arrange a time frame that your goods will be on display and available for purchase through the establishment. It is also important to work out details of shipping to and from and pricing and payment.
The bottom line, there are no hard established rules for doing this type of thing - you just have to figure out what works for you and the person whom you are working with!
Happy 2010 and good luck trunk showing!