There should be a booking button in the client portal when a client logs in to see their profile. This makes it easy for the client to see their past appointments and would help prevent clients double booking themselves. We've had clients who forgot they had prebooked their appointments and then go online to book another. If there was a booking button in the client portal, they'd see this.

We wanted to see the feature and report of "who books who" We have a metric for our staff where we gave bonus to staff who could help rebook clients and this one is super helpful instead of doing/checking it manually