Something I point out a lot in the shop critiques team are title improvements. I've seen some etsians make titles sound like a really complicated effort, throwing around terms like "relevancy" and "optimization"... relax. Those are computer words. We are humans.
So all you need for a good listing title is this: use words that people will search for.
You hold your creation in your hand and you think "this is something I made with those extra zippers in my craft room"... that's what it is to you. But what is it to someone else? A blue purse. If someone wants a blue purse, you have JUST the item for them, don't you? So that's what you should use as the first words in your listing title!
A good thing to do is to use Etsy's search bar to see if people are actually searching for the stuff you're listing in your shop. For example if you type in "tote bag", all sorts of stuff comes up. Lots of people are searching for tote bags, there are even other suggestions, if you make a "chevron tote bag" you're really in luck. That would be a great phrase to start your title off with.
The most common mistake I see is shop owners who want to be descriptive and unique, so they scrape up some descriptive unique words. But shoppers don't think to use those words in search, so they're not helping you. If you type in a phrase and get no suggestions, it's probably not too common.
Etsy provides us with a very nice "shop statistics" page, where you can see what keywords are bringing in the most people to your shop. If you list five similar items, be sure to give them all a wide selection of titles and tags, and see what works best. Experiment and diversify! Maybe some people are searching for a "blue hat" and others are searching for a "wool hat" - if you've got two similar blue wool hats in your shop, give them different titles and you'll catch the eye of both sets of people.
Just remember that your target audience is always the people who come to Etsy with money in their pocket to buy something - that's who you want to find your item. Good titles are the most important tool you've got for that!