The approved drafts features allows you to review, edit and confirm orders placed by your customers before charging the customers credit card.
In order to set this up, you can create a new payment term for your account by going to Dashboard -> Payment Terms -> Create New Terms:
Name the terms to something appropriate, then select the "Charge vaulted card" payment type:
Then, beneath this, ensure the check the box which says "Require admin review and confirmation before order creation"
If you are not offering credit to the customer, then the payment percent and payment due settings should look as follows:
You can optionally set this as default terms for all customers who do not have other default terms applied to their account by checking the below box:
Click save, and you're done! You can now apply these terms to your customer by going to their individual customer overview page.