Hi Kylie
Your listing wording seem ok but you need to work on your titles and tags. For example the first 3 words of a title are the most important so for your grey crocheted coasters I would put "Grey crocheted coasters, pretty grey and orange coasters, Set of 4 coasters' etc - try and use all 150 characters and then tag accordingly. Try not to use just one word tags - "Grey coasters" "Crocheted coasters" etc - you need to repeat your titles in your tags, breaking them down if necessary,
I would join a team that is dedicated to SEO advice, and also, as Jennifer suggested, get active in the forums - a huge amount of expert advice is there.
Good luck :)
