I think Gift Vouchers can be life savers sometimes. Some people are difficult to buy for and to them it would be exciting to browse the shop knowing it won't cost them anything.
On the sidebar there is a button for Gift Vouchers to be used in my Etsy shop. It is via Paypal. All you need to do is click on the button, fill out the particulars on who it is for and how much you would like the voucher to be for and submit. Paypal will make it easy for you.