were it says invoice number just delete the number and type in the invoice number so if its invoice 1 type in 1 if 100 type in 100 simple as that
once you have made up the template with own details on and customers details on make a new folder in my document rename the folder as what ever company you are sending to
save invoice you have made in the new folder
what i do is make new folder in my doc renaim as work folder the open that folder make new folder rename it lets say cleanitup invoice then save the template you have made up for clean it up in there so then you will have a template every time you want to send a invoivce out to that company just change the dates and invoice number just remember to save the new invoice you send for the tax man and back it up as i learned the hard way hope this make sence