Short and Memorable
Make sure it is easy to spell, easy to type and easy to pronounce. Ask yourself “Does the domain pass the radio test?” After hearing it can I type it with out mistakes.
Protect your business name and brand. You can buy multiple domains with different extensions e.g. .net.au .com Make sure competitors don’t register your business name with a different extension
Don’t let your domain name expire. If your domain registrar auto renews take advantage of this
Having keywords in your domain name may increase your google rankings. For example, if you’re launching a mortgage related domain, you might start with words like “mortgage, finance, equity, interest, house” then play around until you can find a good match.
Reject Hyphens and Numbers
Both hyphens and numbers make it hard to give your domain name verbally and falls down on being easy to remember or type. They also correlate poorly with rankings in Google, with branding, and with traffic. I’d additionally suggest not using spelled-out or roman numerals in domains, as both can be confusing and mistaken for the other.