I've been pondering the mantra of "etsy success" for quite a while now, combining it with what I see regarding all the rest of the advice out there -- good photos, marketing yourself, participating in forums, chats, blogs, twitter, etc., etc., etc., until you don't have a second left in the day to create your product.
I think people have it all backwards. You don't list a bunch of stuff and then go everywhere to market it. Sure, people will look. But the trick isn't getting people to look. Additionally, as much as we like the concept of "views", "hearts", and "favoriting", it ALL comes back to placement.
Before even beginning to create a product, take a good look around. What are people listing in shops that carry your genre?
So, let's talk about coffee mugs. OY! Right now there are 243 pages of cups listed in Ceramics and Pottery. A mug is a mug and a green glaze is a green glaze. There are only so many shapes a functional mug can take, so let's put that a aside for a moment as well. In the end, how should one approach a mug that might sell?
1. When I'm just perusing mugs, I usually stop at ones that are eye-catching. This one by gracesheese fits the bill. It's red, it's patterned, and it's photographed against a background that just makes it POP. So, using this parameter, be sure you're making something that will grab the eye against all the other mugs around yours. In this case, color, pattern and background.
2. The next one that jumps out at me is this one by stepanka. Even though it's photographed against a non-contrast background, it just draws the eye because of the surface decoration. Again, it's something different from the sea of mugs surrounding it.
shoshonasnow has this mug that also pulled my eye. This time it was the combination of the color and the shape that did it.
Beyond getting noticed in a general search for something like mugs, you might also want to think about specific "niche" searches you might be able to fill. After all, a mug is a mug is a mug (aplogies to Gertrude Stein). What type of mug can you make in anticipation of things people might search?
One approach would be to check out the holidays. There are all sorts of things that would make a mug a holiday gift: something with familial personalization ("Mother", "Sis", "Best teacher in the world"), for Valentine's day -- a message of love such as this beauty by RedGateCeramics.
Personally, I've decided to enter the Jewish niche market. This works well for me: I'm Jewish, I love giving handmade gifts for weddings, Bnai Mitzvot (Bar and Bat Mitzvahs), and baby showers. I've simply put my ideas on the etsy market and it's been working well for me.
My experience has shown me that a great many of my sales on etsy were not impulse purchases. They were from people coming to etsy with something specific in mind. In my case, it's often a cup for their Jewish mother or father, an end of the year gift for a Hebrew school teacher, that perfect wedding gift for a Jewish couple. I've created product and then tagged it accordingly, so my customers, who don't know they're mine yet, can find me through the search engine (and in spite of rumors to the contrary, that search engine on etsy is still working).
You could just as easily take your products and think about potential searches you can fulfill. How about birdwatchers? Office workers who need a mug at their desk? Kids going off to college and want their mug to set them apart from the rest of the coffee drinkers in their dorm? Dog owners. New mothers and fathers. Outdoorsy people. Couch potatoes. They're all out there and, I'll bet, most of them use mugs. Why not make yours the one they crave????
In short? Etsy product success isn't always in the marketing -- though that's an essential part of getting yourself out there.