I work with agencies and studios as well and cold mails work pretty well for me. Important is to not write to the common email adresses like [hello@whatever.com](mailto:hello@whatever.com). I used to get the linkedin premium account once in a while to get the advanced search. This way I filtered ADs, CDs or producers of the studios I like and get their direct email address (voilanorbert.com is a great tool for... Source: over 1 year ago

Also don't underestimate the power of a cold email - you can quite easily find emails of relatively famous people (using tools like voilanorbert.com) - add value in the email (counter them with an opposing take on something they've said in the past, comment on a podcast they were on and expand the conversation, give them a book recommendation etc) and ask if they'd like to jump on your pod. Source: over 1 year ago

Email Finder: Use something like voilanorbert.com. Source: about 3 years ago

You might get in contact with a nearby university, professor or student organization that have relevant courses to get in contact with students or alumnis. Other sources for co-founders are startup related meetups or websites (e.g., founders-nation.com). Source: over 2 years ago