I think you have to strategize "promoting" because it can become a massive time suck - that being said, these are the things I do on a daily basis:
-Post a photo of an item on Facebook once a day, with a link to my shop (or schedule a post (
http://www.etsy.com/teams/7722/business-topics/discuss/11274820/)-Spend about ten minutes visiting other people's Facebook pages and interacting with them (like wedding photographers, florists, wedding planners)
-spend about 10 minutes a day in the forums :)
then on weekly/monthly basis I do these things:
- write blog posts and schedule them to appear 2-3 times a week
- write an online newsletter
- tweak listing titles, tags or photos as needed
- add new listings, or re-photograph items
- make treasuries
That's about it! If you read the thread I started about scheduling Facebook updates it gives some tips about WHAT to post.