TaxGuyBill
Level 15

Obviously circumstances vary tremendously and it also depends on why and how you want to "scale back", but another possible option is to let clients know that due to the significantly increased complications of tax law, your fees will be going up xx% next year (a fairly large percentage), and that you understand if the client decides to go elsewhere.  

You will lose some clients that way (often the more annoying ones), thereby 'scaling back' on your business, while increasing your profit for your remaining clients.