In addition to sparring with practitioners of my own school/style, I’d like to spar with practitioners of different styles, as I feel this would benefit my fighting ability in the long run. 

*How should this be done in terms of etiquette?* 

Initially the idea of showing up at different dojos/gyms for the purpose of sparring a lone might come across as some outsider presenting themselves to “practice”, aka. challenge. Which is reminiscent of Kung Fu movies in general. I don’t want to be “that guy”. I just want to practice with other stylist without having to sign up for their school.