I'm looking into getting some domains for email, so I don't need to use the same few addresses for everything. In doing this, the domain name itself becomes the identity, but it's also entirely arbitrary.

What is a good method to choose domain names so that they look more or less normal? Catch all addresses can of course be detected in SMTP, but the idea is just to not look suspicious. Would anyone be comfortable sharing the constructions they use? (though not the domains themselves, for obvious reasons) Should I use subdomains for the things that can safely be correlated, (as spam defense) or is it better to only use different mailboxes on one domain?