A simple, but extremely powerful life safer by William Vaughan.
As long as it’s clearly defined, any changes that fall outside of the contract should be greeted with a change authorization form. Even if you don’t plan on charging the client for the changes, it’s a good idea to formally document them so you can track any and all changes that may come up during production. It’s a great resource that has saved my butt several times when a client asks “Why did you change that?” or “Who approved this change?” The form will clearly show why changes were made, who approved them, and how it has affected the project’s time and budget.
You can also edit your form and remove unnecessary details to fit what works best for you or your studio.