Hi, By default it is good to have a return policy and to have it written in the default return policy section and repeated several times. This is my basic policy:
"Returns are accepted for items that are not as pictured and described in the item listing. Returns for any other reason will be decided on an individual basis and refunds or replacements may be approved less shipping costs. Damaged items will be replaced or refunded if a replacement is not available, for insured shipments only, we cannot be held liable for shipping damage on uninsured shipments."
I have this or a variation of this statement saved in my default return policy, terms of sale, shipping, or basically anyplace where I could save statements or that I think that a buyer might look for terms and/or return information. That way it shows up on my eBay listings by default from my preferences along with it being included from my Auctiva profiles that I have setup. Sort of a twist on the repetition teaching model, repeat it several times and it might sink in.