As you have asked for my opinion, I have two suggestions for you.
1. Make at least one of everything you have the impulse to design and bring samples of color variations for each and take orders. For example one cabochon ring in silver and one in gold-filled, each made using a different colored cabochon, and a display box with 5 more cab choices, which gives the customer 7 colors to choose from. In this way you can offer a large variety of items, however, you will have to plan a week or two for delivery, depending on your schedule and how many orders you take. (They can be shipped, delivered by hand, or the hostess can have a 1-hour 'pick-up' at her home.)
2. Choose several different items that you enjoy making and have one full tray of each (one tray of items can by spread out on two velvet boards for display on the coffee table). You may wish to display earrings and a matching cab pendant in the same area (to suggest multiple item purchases).
Overall, depending on the size of the home party, personally I would bring 25 to 30 pair of earrings, 25 pendants, 30 rings, and 15 bracelets (By the way, these are all wire designs, as I do not string) and about 5 designer pieces to be displayed on velvet easels. And I am always prepared to take orders, because no matter how many finished items I have with me, there is always someone who would like something I don't have made up yet!
Answer contributed by Dale "Cougar" Armstrong