How many people do you need for Apex customs?

I'm curious to know, for Apex customs, how many people are typically required to participate in a successful operation? Is there a minimum or maximum number that's recommended? I understand that the nature of the customs and their complexity can vary, but I'm looking for a general idea of the team size that's most effective in achieving the desired outcome. Can you elaborate on the ideal team composition and the roles that each member typically plays?