Depends on the name most names are sold though landing page. The customer types in the exact name they want and see it for sale. Auction sites may help your exposure but it all boils down to whether it is buyers first choice. I like using godaddy as it minimises risk of not getting paid on larger sales even if you have to pay commission. Namepros is a good place to off load fast but don't expect retail. Flippa is only really good for complete websites it is actually less busy these days. Domain niche can also play a part in where you try to sell it. Most people with out a clue about domains that buy domains then ask about where to sell them generally have a name they should be dropping.