Used wedding gowns are getting a second life, thanks to websites such as Still White, PreownedWeddingDresses.com and Once Wed that make it easier to sell a worn gown online. For those looking to part with their wedding dress, selling it can help them recoup some of the costs of a pricey ceremony. And for brides-to-be, the sites can help them buy a used designer gown at a discount. Below are some tips for sellers and buyers.

If you want to sell a used dress:

-- List the dress within two years of buying since older gowns can start to lose value. PreownedWeddingDresses.com has an online calculator that can help you figure own how much the dress could sell for.

-- Know the fees. Some websites, such as Once Wed, are free for a basic listing. But others, such as Still White and PreownedWeddingDresses.com, charge a one-time fee. And remember, you'll also have to pay to get the dress cleaned, which can cost $100 and up.

-- Post as many pictures of the dress as you can. And be prepared to use Facetime, Skype or other video calling service to give potential buyers a live look at the dress, says Shelley Brown, the fashion and beauty editor at wedding planning site The Knot.

-- Be honest about the condition of the dress and point out any damage or permanent stains.

-- Let your Facebook, Instagram and other social media followers know you are selling a dress. Use hashtags, such as .weddingdress, so those who are searching can find your post easily.

If you want to buy a used dress online:

-- Ask questions, request more photos and be wary of sellers that don't give you complete answers.

-- If you need to see the dress in person, many of the websites will let you search for dresses by location so you can find a seller close to you.

-- Most of the sites let sellers come up with their own return policy, so make sure you know what it is in case you don't end up keeping it.

-- Use the online payment method suggested by the site since it might offer you protections from fraud. Once Wed, for example, recommends using Escrow.com because the money can be held until both parties agree to release it. Sellers that ask you to send cash or a check may be trying to scam you.