There are several types of domain names to avoid. One is intentional misspellings, as these make it less likely someone will search for them. You also want to avoid names with extra symbols like hyphens, or with added prefixes and suffixes like "e" or "my." Outside of a few notable exceptions with very strong brands (like eBay), those additions can only hurt the value.[3]
I remember the glory days of the Internet where people did make a ton of money buying domain names. Until I came across this post I actually didn't even realize that people actually still thought they could.make.a.lot of money by doing this. I have some domains that people would be interested in buying and I get contacted about them but mostly it is for people wanting to purchase them for like $1200. And for that price I would rather just hang on to the domain name. I also get contacted by a lot of people offering to sell me complimentary domain names at what I would call ridiculous premiums. The knew google is all about branding. I would consider paying for a domain name that has a great brand attached to it but I could care less about most keyword rich domain names. Of course there are always exceptions.

With over 25 million .com domains registered with Google alone, this top-level domain is by far the most popular choice worldwide. According to the domain marketplace Sedo, in 2015 the average sales price for a .com domain name was over £3000. The most expensive publicly traded domain names have been known to fetch eight-figures sums. But don’t quit your day job just yet: such sales are the exception rather than the rule.

Expired domains are domains that have been registered by individuals, businesses, or organizations, but aren’t renewed after the contract ends, or are deliberately terminated. That means that they available for re-registration. There are many reasons why someone would choose to abandon a domain; one reason could be that the web project failed, or that a domain portfolio went into liquidization. Domains can also end up becoming free due to the owner receiving warnings for possible trademark infringement. Re-registering can also result in legal consequences.
No, no, no. ToysRUs made a perfectly logical decison that most any business would do and Google tanked them for it. ToysRUs wanted the url to direct to their site.  They're all about toys and they simply bought a url that described their business and told the url where to take people.  Google tanked them in the rankings because came with link juice. Google assumed that was doing this to manipulate the search engines but there is just, to my knowledge, ZERO evidence of this.  This is another case of Google caring more about the possible spam threat than the actual rankings for searchers.
Your domain name registrar may provide you with a free one-page Website tool, which you can use to create a “this domain is for sale” landing page. Alternatively, you can create a single page (perhaps a hidden page hanging off one of your existing websites) that indicates that your domain names are for sale. You can then forward all of your domain names that are for sale to that one page.
I OWNED DOMPERIGNON.ORG, incredible, but true.  Lost it, back in the days when internet in India was not a readily accessible utility. And I was a casual domainer.  You had to go to a cybercafe. Did that late in the day, towards the expiry of the domain. No chance of renewal. The domain is now with the owners of Dom Perignon and is redirected to! 
So how do you develop that instinct? NameBio maintains a database of over 500,000 historical domain sales (as of writing this post). They have interesting filtering features by which you can narrow down domains by price range, date sold, keywords and more. Simply sifting through the listings on NameBio long enough will quickly develop your domain appraisal “instinct”.