Create a brand for yourself and for your company - logo, website, portfolio, LinkedIn company page with logo, etc. That makes you appear legitimate to anyone who finds you.

I see too many freelancers or independent 'studios' not spending any time to create any kind of branding for their companies, and people assume that it's not a legitimate operation.

There is a fairly large difference psychologically between seeing a LinkedIn profile that says "Freelance iOS Developer, Self-employed" with no logo and someone who says "Principal, $COMPANY" with a shiny logo. First impressions matter.