If you are struggling to figure out what to sell on Etsy for the first time, or if you need to take your Etsy Shop in a brand new direction because Sales are slowing down, here is the best way I know how to figure out what you should be selling on Etsy.
It is super easy to figure out, and you don't need any expensive tools to do it. Simply look at the keywords on Etsy which are currently trending. Then find a few good examples of other Etsy Sellers that are getting reviews on their products and figure out why people want to buy those particular items. Then, if you are able to quickly make something similar, and the item is something you feel like you would enjoy making or that you are talented at creating, then there is likely a big opportunity in making that product.
This is the easiest way I know to stay relevant on Etsy and to keep making stuff that other people want to buy.