Give each brand its own context
Use separate briefs, sources, design standards and lessons. A decision for one client should not become an undocumented rule for another.
Keep production accountable
Work from campaign goals through drafts and checks. Retain versions so reviewers can understand what changed before making a decision.
Know the access model
A separate customer workspace must keep its data private. Brand organization inside one workspace is different from isolated customer access; confirm the available collaboration model before inviting clients.