Yes, list them at marketplaces. Different marketplaces do better with different types of domains.
Also determine 1) who wants what you have and 2) can afford to spend a fair but healthy price for your quality domain. Figure out how to reach them at a time and place that gives them the benefit of your great asset. For example, if you have RedCar.com you might run ads to people that have that interest, sponsor a red car newsletter, or make useful comments in a red car forum and have the for sale notice in your signature -- just like this! Good luck.