I'll draw up a work-specification and give you a price. Once this agreed, we'll have a contract.
I'll do the work according to what we've agreed and send it to you for your approval.
If there are any changes you need made, I'll undertake a single revision to make the changes you request free of charge. Any further revisions you request will be charged at my normal rate.
Then, I'll invoice you, and you'll pay me within 28 days via PayPal.
Dead simple! No fuss, no palaver! Everyone's happy!