I can only offer you my experience and what I know. My customers are women in their 30's - 50's. They are usually married, work and have disposable income. They love handmade items and the arts in general. They support their local art museums and organizations. They collect handcrafted items. They aren't worried about trends, but see jewelry as an expression of their individuality. They love to give gifts that are meaningful and well thought-out.
My best shows are art fairs and shows that are hosted by arts organizations. I wouldn't do well at a country-craft type show. My customers aren't there. I do better in urban areas in larger cities. Knowing these things about my customers and where to find them helps me plan shows that have a greater chance of success for my style of jewelry.
Where to find shows?
*Ask other artists/crafters.
*Go to shows and see what events your favorite artists are doing.
*Get connected with the local art groups in your area.
*Find out if your state has an arts commission or council, here is a list of them.
*Network with guilds/societies in your area. We have a fiber arts guild & a bead society. Both put on shows for their members and announce upcoming shows in the community.
*CraftLister is a list of craft & art fairs.
*Looking for big shows? Sign up for Zapplication, most of the larger shows use this service.
In general, it's better to attend a show before you sign up for it, especially ones that charge higher fees. Stay away from 1st year shows, it's such a gamble. Exceptions would be organizations that you want to support.