If you are trying to break into any field, it is important to get credentialed. One way to do that is to offer some sort of reviews or perhaps do some free consulting work, in order to establish yourself as a ‘guru’. For example, if you are starting a HVAC business, you might try to have some free heat pump reviews published, or you might offer your services for a time as an online consultant (via email) to those with heat pump problems or installation issues.