1. Determine your strongest keywords.
You can get all fancy and go into Google AdWords' Keyword Tool and find out what people type into search engines when they are searching for the items you sell. Or you can go to your Etsy stat page and scroll to the bottom and see what phrases are leading people to your listings. Take those top 2-3 phrases and write them down.
2. Open up a listing and to Edit it
Take those keyword phrases and make them the FIRST words in your product title. Try to see if you can use a variation or a second keyword phrase again in the title.
3. Make the colon your new best friend.
After your keyword phrase in the title put a colon, you know, the thing that's the eyes in a smiley face :). Now write the rest of your title for people (instead of for robots) - use descriptive words, colors, etc.
4. Edit your description
Using the same keyword phrase from your title, put it one or two times in the first paragraph of your description. Write the rest of the post how you would normally describe it to a potential buyer (so, probably leave the rest of the description alone)
5. Edit your tags
Make sure you have your exact keyword phrase in your tags. Don't split up the words in individual tags. If you are trying to rank for "goat milk soap" then make that the whole phrase your tag.
That's it! Do that for a couple of listings a day and eventually you'll get through your shop. Search for yourself with that key phrase - you should pop up on the first page - if not, keep tweaking it, front loading the key phrase a bit more until you do.
This has been working great for me since the switch to relevancy. I'm curious what other tips are out there...