I'm adding people to the workspace. Who should be an Editor and who an Admin?

Make the people who build budgets Editors, and make the one or two people who run the team, the workspace settings and billing Admins. Everyone then has what they need on day one, and Project membership decides which budgets each person sees.

What each role does

An Editor works freely in every budget they can see. They create and edit budgets, create a Project, and see who is on the team and which invitations are outstanding. Day-to-day budgeting is identical for both roles, so an Editor never waits on anyone to get their own work done.

An Admin does everything an Editor does, and also looks after the workspace:

Team. Invites people, changes someone's role and removes members.
Workspace settings. Manages the Labels and Units your whole team picks from, so every budget uses the same vocabulary.
Billing. Sees Plan & billing in Settings, including the seat count.
Clean-up. Deletes a budget that is not filed in a Project.

Add people and choose their role

Open Settings, then Administration, then Team.
Click Invite new Member, put one email address on each row and choose Editor or Admin beside it. Editor is the starting choice.
Click Send Invitations.

To change a role later, open the row menu for the person on the same Team panel. Promote to Admin makes them an Admin. Downgrade to Member sets them to Editor, and the Role column reads Editor afterward. The change takes effect the moment you click it, so tell the person directly.

Splinde always keeps at least one Admin in every workspace.

Project membership decides which budgets someone sees

A role says what someone can manage. Project membership says which budgets they see. A budget filed in a Project is visible to that Project's members, and a budget that is not filed in a Project is visible to everyone in the workspace. So the full picture of access for any person is their role plus the Projects they belong to. The steps are in How do I make sure freelancers only see their own project?.

A good default: Editor for producers, production managers, accountants and freelancers, Admin for the person who owns the team and the billing.

Check a role

Open Settings, go to Preferences, then Your Workspaces. The Your Role column shows Editor or Admin for each workspace you belong to. The Role column on the Team panel shows the same for everyone else, so you know whom to ask about team or settings changes.