The best way to get a self-signed certificate trusted is to go through a Key Ceremony, which is basically a big public event where all cryptographers and security experts gather together to witness a root CA generate their key-pair and declare themselves a root CA. Everything is recorded: video, who everyone is and what everyone does by lawyers. The private key is split into many different parts and stored separately in safes typically after signing a single certificate which is used as an intermediary to sign other certificates. You can read about the typical procedure if you'd like. Of course, you need to have state of the art security, both technological and physical, to do this and have anyone want to use or trust your root CA. After doing this your certificates may be included in browser distributions and then can be used by the general public to create trust chains of certificates.