If your domain name is related to a particular niche, then you may find success by advertising in forums that are related to that niche. Simply placing a link in the signature of your posts can tremendously speed up the selling process. While it may be possible to find prospective webmasters on niche-specific forums, it is generally better to advertise on webmaster forums, where there is a high volume of potential customers.
The third option is the one that's the most time consuming but also has its benefits. It's like having a successful restaurant and buying another restaurant and operating them simultaneously. They're not the exact same restaurant, but both are popular in their own right and make you money. The same goes for Option #3. You could update the content on the old domain and sell the same products that you're selling on your current site. If you can get both sites to rank alongside each other in the SERPs, you're increasing your conversion chances and sales potential. 

Here's an old post on search engine roundtable that claims google's policy is to discount previous backlink juice when a domain changes ownership.  I'm not convinced whether this is actually true or something Google says to discourage excessive domain buying / 301 redirecting for SEO benefit.  The comments above seem to give varying opinions on this matter. Would be great to get to the bottom of that one!
Let’s just say for example we wanted this site, crystalgiftsworld.com. It looked good based on our analysis and we’d head over to Snap Names, Nameja is another one and what these service do is they have special technology on their site that allows them to try  to register a domain on your behalf over and over again. Okay? If you tried to do that your IP would get banned, but they have some system where they know how to do it just enough to get the domain, but not enough to get blacklisted.
In order to maintain ownership of a domain, you must renew it yearly. If you don’t, it “expires”. An expired domain goes through several stages before being released again for general registration. The process differs slightly from one registrar to another but it’s more or less the same. GoDaddy explains what happens to domains that expire with them here.
All very relevant points for anyone wanting to sell a domain name. Sometimes it is the basic points that we need to be reminded of in a transaction like this. What is the potential of selling a .com domain that has a relevant search term to a particular industry, but hasn’t been used on a website yet? So it is a good search term but no current traffic.
There is always a learning curve in buying domains with the purpose of reselling them. Don’t hesitate to ask a lot of questions to those who went before you, participate in forums such as namepros.com and dnforum.com, keep abreast of industry trends via resources like domaining.com, and reach out to the Afternic and GoDaddy Aftermarket support teams.
Get appraisals for your domain names. When selling, you will want to know what kind of price you should expect to get for your sites. There are a variety of websites that offer free appraisals for valuation. This includes larger domain auction sites such as Sedo.com, GoDaddy.com, and DomainIndex.com. These of course are only estimates, but they can give you a good idea of what certain domains might be worth.
Sir I am a newbie and a lot interested in doing this business but I don’t know fron where and how to start it. How to purchase where I have to pay and how I have to pay all sort of questions are there in my mind. So sir if you could email me the details then it would be of great help. Its been months searching but I hadn’t purchased any domain yet.

Buying and selling domain names is an exciting adventure that for some seems to conjure up images of finding hidden pirate treasure or guessing the winning combination on the next Powerball. Stories abound of domains that were purchased for $8 dollars 15 years ago being sold today for millions. Of course, that leads the more adventurous of us to wonder, “How can I do that?”
Dictionary Word/Pronounceable/Memorable/Brandable: A dictionary word domain name is very valuable. Of course, the more popular and widely used the word is, the better. For example, “marketing.com”, “cars.com” and “hotels.com” are 7-8 figure domain names. Even if a domain name isn’t a dictionary word, being pronounceable and/or memorable and/or brandable are all big pluses that add to its value.