SEO is simply 'Search Engine Optimization' or a fancy term for 'using titles to call your items what they are'.
So if you are selling hair bows, then each title should contain the phrase 'hair bow'. If you are selling a cuff, then the title should contain the word 'cuff', and so on.
You can mention the materials used in the piece and the colour in the title if you wish.
I've found that the best way to write a title is to start as if you are showing your latest creation to your friend. What would you say? 'Hey! Look at the neat new XXXXXXX that I just finished!
That XXXXXX then becomes your item title.
To select tags, simply start with the words and phrases from your title and go from there.
As for getting exposure, you need to be marketing directly to your customer. Who is most likely to purchase what you are selling? Where are they? That's where you do your marketing.
You may find that the 'critique your own shop' blog post at
etsymentors.blogspot.com/p/critique-your-own-shop.html
has some other useful tips as well.