The second option requires a bit more time and effort than a 301 redirect. You could do a mini overhaul of the site and turn it into a microsite for your main domain. This option is good for exact-match domains for your targeted keyword, and there are other reasons for going the microsite route that Rand's highlighted in his post about root domains, subdomains, subfolders and microsites. This strategy also works better if the old domain has decent rankings for the keywords you're targeting. 

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!
These should be more than enough to get your domain in front of tons of potential buyers. If you did a good job picking an awesome domain, you should have no problem (eventually) selling it. You need to be very patient as it could take months or even more to land a decent deal. A lot of domainers sit on domains for years before actually selling them. This is why it’s best not to obsess over a domain and simply move on with buying and listing others (or going back to your day job if this is a side gig) once you've listed the initial one.
Before EmpireFlippers became a website broker, the internet marketing duo Joe Magnotti and Justin Cooke had been sharing how they flip sites for cash on their widely-popular blog and podcasts. They relocated to the Philippines, hired locals to create content and build traffic, and then literally built hundreds of niche sites that earn from either AdSense ads or Amazon affiliate commissions. Every month, they chose low-earners and sold these ready-made sites on their marketplace.

Some buyers are a tough nut to crack and they may quote a ridiculously low offer. Explain to these buyers and convince them why the domain is worth more than the quote. If the potential buyer doesn’t agree, fret not, just move on to the next one until you find a willing buyer. Once you finalize the deal, then it’s time to find the best payment mode for the transaction.
The "Domain Lists" and the "TLDs" filter are now static and not created dynamic based on the current search. Turns out creating these 2 filters dynamically was slowing down the search tremendously. It even made certain requests impossible. For example now you can do a dot search that affects all .com domains and get a result with over 150mio domains in reasonable time. I'm also working on a new search cluster that will make searching even faster (not released yet).

In the grey hat SEO world, the thought is that you can take a domain that is keyword driven, do a quick optimization to get the site ranking, and sell it off at a profit. It could, and does happen daily. How much time is invested in optimizing a site to get to page one, vs how much the site will sell for? (remember that quote at the beginning of this article?). Let's put it into simple math:
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If you don’t have a lot of money to invest in employees and you’d rather work on your domain portfolio by yourself, you’d need plenty of free time. Generally, mini sites with 5 to 10 pages of content can be built within 5 days, while authority sites with over 10 pages could take up to two weeks. This amount of time would depend on your writing skills and knowledge of SEO techniques.
Simply put, domain flipping is the process of acquiring a domain name with a motive of selling it at a higher cost to someone else. This is very similar to flipping houses or cars, the only difference being that you can’t do much to increase the value of the asset by ‘fixing it up’ and then turning it over for a quick buck. Acquiring a valuable domain name before it is tagged with a premium price is the key to a successful domain flip. Raymond Hackney, a domain investor and consultant, successfully flipped a .website domain (his first on a new domain extension) for a decent profit. Read all about it here.
Official marketplaces offer a third possibility for domain traders to peddle their product. Domain marketplaces, such as Sedo, GoDaddy.com, or BuyDomains.com, link potential buyers with domain holders hoping to sell their prized virtual property. These platforms function as a kind of domain real estate agency and are known to demand somewhat high prices for their services.
Using the keyword search feature you’d also be able to familiarize yourself with how much domains typically cost on average in a certain industry or niche. Even better, they have an addictive little app called “The Domain Game” available for iOS and Android. They basically give you a domain and you try to guess whether it sold for three, four, five or six figures. You get points for each correct answer and lose points for incorrect ones. You do this for a while and you start to see patterns. Your brain starts connecting the dots and you get better it. Now you’re ready to go out there and scout some domains!
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