With some time limitations, I accept returns and provide a full refund if a piece is defective or a I make a definite mistake in describing the item. And I will exchange an item for another of equal value if the purchase doesn't work out for a purely personal reason.
But I can't produce enough stock to be able to send people my work to try on. Mail from Canada and back can take weeks.
95% of my business is local, not mail order, and I can not advertise one set of policies in my Etsy shop and another for local people who read these policies. If I do not have a piece for even a few busy hours at our local Market, I may have lost several opportunities to sell this piece.
I would have to make a lot more money than I do now to be able to shrug off a few lost sales because of indecisive customers. Maybe offering a 10 day no questions asked return policy would improve my sales and make up for the occasional losses. Maybe not. Someday maybe I will be in a position to offer a 1 month special where I allow this, and see if there is a really positive response. But at this time of year, when I am scrambling to keep my stock up, there is just no way I can offer that kind of mail order customer service.