Don't give out any copyrights you don't have to. Make sure you keep track of all business calls, mailing expenses, mileage, and everything you have to buy, and record them clearly. There are several good computer programs that will help you do this , but even writing everything down in a simple notebook will suffice. Use fax machines, overnight couriers, etc. to get things there on time. If you absolutely can't get it done in time, let the editor know as soon as possible.
Editors are human.
They know life sometimes get in the way. But they appreciate being told ahead of time. Often they can make adjustments. Keep a journal. Write down feelings as well as ideas.