To make borders for letters using a word processing program, open a new document, and format borders in the page layout section. To make borders by hand for a non-formal letter, use craft scissors to cut a patterned border, use a rolling ink stamp, draw a border with metallic leafing pens, or create a burned edges effect, depending on the purpose of the letter.
A business letter's border design is minimal, professional and elegant. Use a word processing program for any formal document. When formatting the border, choose a color and design that suits the business or organization for which the letter represents. There are border designs with simple lines, as well as more elaborate imaging or edges. If needed, add a letterhead using the header or footer formats.
Once the border is as desired, apply the design to the document. Open the page in a print preview window, or print a test page to ensure the border is aligned properly. If there is a discrepancy with any of the edges of the border, adjust the measurements used to outline the page in the border or page layout menu.
For personal letters, invitations or letters written for creative purposes, embellish the edges in a more interesting manner. This is done either with the more whimsical border designs in a word processing program or by using craft and scrapbook materials. Use thick stock paper, and apply stickers, gems, embossing or any other material that is relevant to the purpose of the letter.