Sometimes we go months without thinking about a topic and then twice in a single day something comes up, like today when in depth conversations about keywords and SEO blossomed...
Tuning your website for keywords can be tricky. If you had a choice of tuning your website for only 5 phrases, what would you choose? Do you sell just 5 types of jewelry in your store? If you wanted to tune your website for "engagement rings" and "diamond engagement rings" that would already be 2 phrases. You could easily end up with a list of 20 or 30 desired keywords and phrase permutations.
From our point of view you should not be trying to narrow down SEO to a limited set of keywords, simply because that's not natural. Imagine if you were told to have a conversation about the rain storm outside, but you were not allowed to use the word "weather" during the conversation. Limiting yourself to specific keywords on a single page of your website is just as silly.
Instead, you should pick a topic and add any content you want to a single page. Just make sure the entire page is about that dedicated topic. Web pages come in all types: blog, news, educational, product catalogs, and normal content pages which explain your store and services.
Speaking of services, the Services Page of many jewelry websites is one of those multi-purpose pages that cover various topics like watch repair, pearl restringing, custom jewelry design, appraisals, etc.. If you have enough to say about each service then describe it in detail on its own page.
So, tuning a page for a single set of keywords is not needed as much anymore as tuning a single page for a single topic. As you discuss the topic or tell a story about the topic you should find that the natural keywords and phrases will emerge throughout your writing.
Another point about keywords is that different keywords are popular during different times of the year. The word "jewelry" is very popular in December and February, but not so much in March or September each year. The word "locket" is very popular in December and May, but not in March or June. Therefore tuning your website for various keywords needs to be completed months before their peek popularity; otherwise you've missed your website window of opportunity.
For you, the easiest keyword strategy is to tell a story. You must have stories about previous happy customers who used each of your services. Maybe you did an appraisal for an old estate piece found in a dusty shoe box hidden in an attic; or maybe you custom designed an engagement ring for a guy who had the worst case of butterflies.
If you took a moment to type out each of these stories, they would be loaded with natural, keyword rich, fresh content for your website. Make sure to describe the jewelry item you sold or worked on and how the customer selected it, and how you satisfied all the concerns they might have had. Tell a story about every topic you can think of, every holiday, no matter how trivial.
A funny thing will happen in your website stats as you continue to add stories into your blog. You will see the visitors to your blog pages increase. Your blog will attract new visitors every month, and a few of those visitors will click through into the rest of your website. From there you have the potential to gain a customer.
If you have limited time and a limited budget, spend it on blog writing for your website. Blogs are keyword rich and extremely important for SERP ranking.