Scope creep does not arrive all at once. It arrives as five small favours that add up to a week you never billed.

Say the words out loud

"Happy to do that, it is extra, I will send it over." One sentence, said calmly, protects the whole job.

Put it in writing the same day

Description, price, new completion date. Memory is not a contract and neither is a text that says "sounds good".

Get a signature before you start

A tap on your phone is enough. Work that starts before approval is work you are gambling on.

Review it at the end

Walk the change orders with the customer before the final invoice. Surprises at invoicing are how good jobs end badly.