
One that doesn’t take corporate donations would be start.
Another method is 3rd parties forming locally as grassroots organizations and then forming a coalition party to back 3rd party candidates on the national level.
Sort of how you have a few caucuses in the Democratic Party like the Farm-Labor Part in Minnesota, or Independents who caucus with the Democrats like Bernie who could be peeled off to back a 3rd party of even just flatly Independent candidates.
I had a friend who went through a whole arc of wanting to be a cop. She had pretty much an identical experience I had to squint at the name and photo to be sure this wasn’t a post she had made.
Being a woman was a huge setback from the get-go anyway, casual police brutality training notwithstanding.
She never quite got my criticism of wanting to be a cop (She wanted to fix policing by example) nor my lack of surprise when she spent a year wasting her time being tested and strung along by cops who were never going to hire her. (You have a master’s degree FFS! You’re not what they’re looking for!)