Spend 5-10 minutes reflecting on what has gone well and what has not worked in the past on a post-it note. Each team member should write 5-10 points with no more than 5 words on each post-it. 

Arrange the post-its in a matrix for easy viewing.

Allocate some stickers (or digital dots) and ask them to place one dot on principles they like and 2-3 dots on principles they love. This technique is called heat-mapping. 

When everyone has placed their dots, step back and see where the heat is. It is usually clear which principles should be used and which should be removed. Spend some time discussing the results of the heat map. 

Allocate a person to draft the team charter in a shared Google Doc, so the rest of the team can amend it later. 

Set a strict deadline for the completion of the charter. Once it's ready you can start to implement it as a team. 

The charter should evolve over time. Pilot your charter draft for a set amount of time. Spend 5 minutes at the end of online meetings reflecting on how effectively the team embodied the principles. After your fixed period, bring the team together for a more in-depth reflection. Make updates based on the team's reflection.