Don t worryebay will have already sent them an invoice to pay for their item.You can start to worry after about 5 days if they have not paid-send them another invoice by going into the sold listing details send invoiceiF after 7 days the have still not paid (they will be unlikely to now) do a dispute in ebay for non payment-they will get a reminder to pay(if this dosen t wake them up nothing will)You will get your listing fees back and they will get a strikeIf they do happen to neg/neut you; you can have it removed.Dont send a false positive on their feedback- be clever and word it properly or they can have it removed
Many larger business like Amazon etc will enclose a document with the order which says how much it cost, then name and address of the buyer. And include your contact details and what to do if they want a refund or have any problems with their purchase. It just looks more professional
eBay will automatically send an email that says you ve won and it has a pay-now link in it to Paypal.