Many conferences and in-person meetings have transitioned to virtual platforms in response to the COVID-19 pandemic. Here, we share strategies and lessons learned from organizing an international virtual unconventional conference, or ‘unconference’. The event focused on how early career researchers can advocate for systemic improvements in scientific publishing and research culture. The virtual unconference had three main components: (1) a virtual networking event, (2) asynchronous virtual brainstorming, and (3) a virtual open space, where participants could join or lead in-depth discussions. The unconference format was participant-driven and encouraged dialogue and collaboration between 54 attendees from 20 countries on six continents. Virtual brainstorming allowed participants to contribute to discussions at times that were convenient for them. Activity was consistently high throughout the 48 hours of virtual brainstorming and continued into the next day. The results of these discussions are collaboratively summarized in a paper entitled Empowering Early Career Researchers to Improve Science, co-authored by the unconference participants. We hope that this method report will help others to organize asynchronous virtual unconferences, while also providing new strategies for participant-driven activities that could be integrated into conventional virtual conferences.