Before switching the payment type on your account, make sure to communicate the change to your patrons! Once you've shared the news of the switch with them, here is how to change your payment type for your account:
From your creator page, navigate to the top and click "edit your page."
Click "edit" on the module on the top-left where you see the number of patrons and amount per "month" or "creation" listed. You should see a payment settings pop-up open.
If you're switching to "per creation," enter what it is that potential patrons will be paying for when they become your patron. If you're switching to "monthly," you will not need to enter what it is you create.
If you are in the "charge up front" program, you will not be able to select the 'per creation' option from this menu.