The Answer: Consultancy.
I haven't sold jewelry, but I've sold six and seven figure gigs. This is a good approach for people uncomfortable with flattery and "persuasion" or glad-handing or cajoling or becoming "friends" with a customer, people uncomfortable with lying about discounts and one-time offers that aren't really one-time. People that aren't good looking or charismatic, for that matter.
It requires some knowledge of your product and how it is used. You can be yourself! (if yourself is a person interested in making a profit by truly satisfying a customer with your product).
This relies on a universal truth: People love to talk about themselves.
First, understand your role and attitude: You are a specialist trying to solve a problem for your customer, but put yourself in a servant role (as most doctors do when trying to understand patients that need help). Dress and act the part (not of a doctor, but this is a similar dynamic). So no ripped T-shirts or sandals; wear a button shirt, pants without holes and closed shoes.
Begin with open questions about their situation for this product probably two or three at most. Perhaps here,
"Are you looking for yourself, or are you looking for a gift?"
"In what kinds of situations would you (or she) wear pieces like ours?" (Examples to help them out: at work? Romantic outings? Events or concerts? Business meetings with clients?")
"Is this for a particular event, or to add to your [her] collection?"
"What would you say is your [her] favorite piece to wear?" (if not in the answer, "What kinds of occasions do you get that out?"
Listen to the answers, These are not idle questions, they need to shape your responses and the range of prices you offer.
Somebody "just looking for something fun" is looking for a bargain. Somebody attending a business function (promotion party, client meeting) will buy something more expensive; they don't want it to look cheap. Those are the people you can tell about the provenance; it is something they might use; "I fell in love with this piece, it is made by moon elves in a cave in the Philippines," or whatever it is that makes it special.
Next, figure out the constraints. Why hasn't she bought something? You know the type of jewelery she is looking for. Say something like (in your words, same ideas) "So you haven't found what you're looking for yet, how would you describe what speaks to you? Is it more the colors or the pattern or the size?
How about on this tray, can you point out a More Like This, Less Like That kind of example?"
Again, Listen, and analyze. By talking about themselves they have narrowed your options.
Your next step: Solve their problem (or tell them your products might not fill the bill).
"Let me try a few things, and you tell me if we're on the right track."
Keep up the interaction, ask her for guidance. If she settles on something, or a few, try to close: "I think that's it, this one [any of these] can get the job done. What do you think?"
If the close doesn't work, move back to a question. If you detect you aren't going to make a sale, be polite but stop trying to help. "Well, I'll let you think about it, just let me know if I can help."
Feel free to compliment them if it feels natural; personally I would talk about how I feel about it: "I love that piece, whoever designed that has an eye for contrast [or drama, or natural lines, etc]." Just make sure you keep telling the truth, it is crucial to the method: People detect lies and empty compliments quickly, even subconsciously. If you are telling the truth and sincerely trying to help (and know your product) you will make sales.
You are aiming to solve a problem, even an impulse buy of a frivolous item is helping them have some fun in life; that is usually why they are standing at your table.
Do NOT think you are intruding to take the initiative with them, many people are shy, and most feel like if they start, you will expect them to buy something, or they will feel obligated to buy something for taking up your time, so they don't start! If you FAIL to engage them you haven't done your job, and without your help they may have missed out on the fun they were seeking.
Don't do that, ask them a question. Then YOU started this thing, and they can proceed to shop without obligation. Maybe they will open up and you can help them find something fun, that in weeks to come they will still be happy they bought. From such a nice man!