A short and easy name that the customers and visitors will associate with the website, avoiding hyphens and special character names even if the name is long. Using the company name is usually the best idea. For businesses, I think a .com or a .net extension and for information sites a .info would be good.
Registering similar domain names with different extensions, with the help of this you donโt need a separate web page for each of those names, several domains can point to the same website.
It is possible that a name that may make perfect sense to me but may be too hard for them to remember, in this case I take opinions from friends and clients on the domain whether it is easy to remember and spell?