How to sell domains?Koeln, )
You should make a website and/or a blog, which offers the domain.
Don’t forget to use hints at the whois entries like nameservers named ns.this-domain-is-for-sale.com.
If you want to sell a domain name, you should be active.
You could contact the owners of similar domain names and ask them, if they are interested at your name.
If you want to resell domain names, you should ask one of the existing registrars (like Secura GmbH) to become a reseller.