Ideally your domain name should sound exactly as your brand or company name or, at least, reflect it to some extent. Unfortunately many of the domain names using popular words are already taken. If the name you use for your business uses a combination of popular words, chances are it is taken as well. Start doing your search and if nothing shows as available to resonate with your brand, get creative. Slightly modify your brand name pronunciation, add your location, add action verbs and adjectives and see if you can find more options available for registration.