Obvious stuff:

• Learn about trademarks and don’t violate others’ trademarks. Trademarks are complicated, so learn about what is and isn’t likely to be a violation before you waste expensive lawyer time on this. A good general rule is that you don’t want the same name as something in your same industry, but overlap with different industries may be OK.
• Try to make it short and easy to spell. Think ahead of the ways that people will misspell it. Ask your least-educated friends or family members to spell it. If they can’t, reconsider.
• Try to differentiate. Avoid names that sound or look a lot like some other name. Best case your customers will get confused. Worst case you get sued.
• Think about connotations and match connotations to what you want people to think about your product or company. “Google” sounds cute and friendly. “Amazon” sounds huge with big capacity. “Palantir” sounds like science fiction and kind of scary. “Protogen” (fans of The Expanse TV shows/books will know this one!) sounds generic and not scary at all, which is good if you’re a totally scary secret bio-weapons facility.
• If you want to grow internationally, think about what your name means in the most common global languages (Spanish, Chinese, Japanese, German, Arabic, etc.) Don’t be the Chevy Nova where “No Va” means “Won’t Go” in Spanish.
• Google for “how to name my product”. Lots of good info there— millions of people have already done this before. Don’t rely on Quora for all your advice.
• Be aware of “name trends” and try to avoid them. For example, there was a trend in the early 2000’s (probably started by Apple) to have one lower-case letter at the start of the name, e.g. iPod, eLance, oDesk, zShops, etc. A trend around 2010 give or take a few years was to take regular words and omit vowels, e.g. Tumblr, Grindr. Don’t give in to these kinds of trends— in a few years they’ll make your app look like parachute pants or leg warmers.

Non-obvious stuff:

(I just finished two different naming exercises, so these were interesting things I learned in the process)

• Survey your customers (or potential customers) about many prospective names. I just did this with about 30 potential names and got a lot of useful feedback that influenced our choices.
• Think about auto-complete. Most people will be finding your product or company through a search engine, like Google, a mobile app store, Amazon, etc. Most of the time, the user will never type in your entire name— instead they’ll type in a few characters and rely on auto-complete to pick the actual name. So a winning name these days contains (or, ideally, starts with) an unusual sequence of characters. My favorite example is “OKCupid”, where you only need to type three characters to find it because “OKC” is not a common set of characters.
• Think how people will shorten it. For example, “Microsoft Windows” is the full name of the product, but everyone calls it “Windows”. If your name is good in its entirety but not good when shortened by real people, then keep looking.
• If it’s a company name, think about what you’ll call your users and/or your employees. A name that can be adapted in this way is great. For example, “Googlers” and “Redditors” works well but “Oracles” really doesn’t. ;-)
• Names that can be turned into verbs (e.g. “Google it”) and/or adjectives (“Googley”) are also great when it comes to driving your brand at scale.
• Personally, I really don’t like DumbNames that have TwoWords. Just because you can GlueLetters the implication is that you’re somehow high tech. The best names don’t do this— having two words with a capital letter in the middle is, IMHO, a shortcut to finding a really good name that stands on its own with normal capitalization.