Hi Martina, it takes a bit honestly..I wish there was a faster way but it took me a couple of months :(
This team helped me out a lot!
And also this other team helped me with the tags and keywords:
http://www.etsy.com/teams/11352/relevancy-and-seo-for-all-etsy-shopsPlease check it out! And talk with this team too!
Also, I use PICASA to edit my pics. You can download it totally free on Google (this was an advise from another ETSIAN).