Client Notes are best kept as alerts. Client Alerts are always available whenever the client is in context (editing the client or doing anything with a patient associated with the client).
To manage a clients alerts, go to any location where the client is in context and then click on the lightning bolt menu in the upper right VetBadger menu.
From here if you click on the first menu item ('Alerts for Zoe Adams.' above) you will be able to manage the alerts for the client. Alerts are available whenever a client is in context and can have a priority associated with them as well.