Maybe because I LOVE writing, I love to blog. I wouldn't put too much emphasis on what needs to be said - just say what you feel, your current interests, your etsy shop. Speak from what inspires you, even if you just make a post of photos you found around the internet.
Your shop is jewelry so perhaps a blog on an emphasis on accessories and jewelry you like, your own jewelry, etc. is a place to start off with.
When I started my blogs, I came up with 15 post ideas. Perhaps try the same, work on those blog posts, and see where it takes you!
I have three blogs (shameless promotion:
http://www.thedramallama.net,
http://www.potterblogger.com, and
http://www.flairfulliving.com) - I just invest my time and interest into each one, and it really does pay off. I feel much more creative and passionate for each blog with every post - but I just take it one post at a time. :D
Good luck!