Go to Your Houzz, then click the Ideabooks tab in the navigation bar next to your profile picture. Select the Ideabook you want to share and click the Collaborate button. Add a collaborator by searching for their username or email. You can also decide whether you want the collaborator to be able to edit the Ideabook, or just view it.
If a client has added you as a collaborator to an Ideabook, you will receive an email notification.