Plans and diaries are the substance of the service. Held with the notes rather than scattered across email, they can be reviewed in the appointment instead of reconstructed from what the client happens to remember.
Programmes are blocks, not appointments. Four sessions bought together need tracking as a unit — how many used, what remains, when it expires — or the practice ends up giving away the fifth.
The messages between sessions are the work nobody bills. A question on Tuesday and a substitution suggested on Thursday are real professional time, and deciding openly whether they are included is better than resenting them.
Measurement is what keeps someone going. Whatever the marker, recorded at the start and reviewed at intervals, it is the difference between a client who continues and one who drifts away convinced nothing changed.