I finally decided to buy Mary's SEO guide shown in the OP, as I'm getting very little traffic via searches, the majority is direct to my shop. Although I've read a number of posts with regards titles and tags within this team, I just couldn't get it to "click", but reading through Mary's guide I think I'm finally starting to understand some of this SEO stuff. I've just redone three of my listings ~
When searching using "rose quartz pendant" went from page 12 to page 1:
http://www.etsy.com/listing/93897378/rose-quartz-pendant-in-sterling-silverWhen searching using "rose quartz necklaces" went from beyond page 30 (I have no idea exactly what page it was on I gave up at 30) and is now on page 2:
http://www.etsy.com/listing/93897473/rose-quartz-necklace-in-sterling-silverWhen searching using "rose quartz necklaces" went from beyond page 30 to page 2, and using "pink crystal necklace" went from beyond page 20 to page 1:
http://www.etsy.com/listing/93303813/rose-quartz-necklace-pink-crystalNone of these listings would easily have been found before as they were too buried. So a big thanks to Mary! It's without a doubt the best money I've spent so far on my business. Now I've just to go and do the same and update all of my other listings!