The next time you're selling in a face-to-face situation, try to stand alongside the prospective customer instead of on the other side of a booth or table.
Being on the "same side" as your prospect can reduce resistance. It also reduces the discomfort -- for both buyer and seller -- of those moments when they are looking at your jewelry, and you are looking at them from the opposite side of the table or booth.
If you think about all of the expressions that have to do with disagreement, the often have to do with being on the opposite side of someone else. "We were really butting heads!" is one expression that comes to mind. Or "We're just coming at this from opposite directions."
Try the technique of standing near the prospect instead of across from them. You can be facing the same direction, or turned in toward them as they peruse your jewelry.
Another great tip is to have mirrors that people can see themselves in. It's much easier to look at their reflection when you're standing next to them, then when you're on the other side of the table or booth.