Correspondence cards often have a colored border, and while it’s appropriate to put your name across the top, having your initials in the corner in the classiest way to go.
You may add just your name, or your name, address, and coat of arms to the top of the sheets.
They can be used for longer missives too; just order plain sheets for additional pages.
As with all stationery, the first page can be embellished with a monogram or design while additional sheets should be plain.
Do not write on the back of these sheets; if you need more room, continue onto a new page.