I use Ebay to sell all my domain names and websites and have had a pretty good success rate, I'd say.
You can check out my past auctions at
http://www.developeddomains.com/ebay
I always do the following.
1. Always
BOLD (Only $2 and it makes it stand out more than a highlight)
2. Always Feature it ($19.95)
3. Never use the gallery or featured gallery.
4. Start all auctions at $1
5. I never use the Buy It Now option. Too risky since someone could set up a bogus account, buy it now, and not pay. Some sellers will do this so their auctions have less competition.
6. I always make my auctions private. Many bidders don't want to be shown that they are buying a domain name. They'll get mass spams from other sellers trying to sell them other domain names. This also protects me, since many users will email your bidders to try to pursuade them not to buy or they have something better, etc. Bad business, but it does happen.
7. Make your description as detailed as possible. Remember, this is your sales pitch to buyers. Make it good!
8. Use the free counter. It will show buyers (and you) how popular the auction is.
These are my personal preferences, so you'll have to decide what is best for your auction and what you want to spend.
Most of my auctions are for complete websites and yahoo listed domain names, so they have more value, but it should work for single and multiple domain names as well.
Hope this helps! Good luck in the auction!