Place some acid-free parchment paper, heavy stationery or card stock on an ink blotter on a desk or workspace. Be sure to select paper in a color and style that expresses your personality. Also get a quill or fountain pen and a bottle of ink in a color such as black, brown or blue.
Look in a book of poetry for romantic stanzas that express the love that you feel. Favor the work of romantic poets such as Elizabeth Barrett Browning or Emily Dickinson. If you prefer, write your own poetry on a separate piece of paper in pencil. The poetry doesn't have to rhyme. Free verse poetry is some of the most beautiful poetry that has ever been written.
Write down the things you really want to say to your loved one. Write about the things you love most about this person, the good times you remember having together and your hopes for the future.
Write out your letter on the heavy paper in ink when you're ready. Begin the romantic letter with an opening such as "My Dearest." Close it with "Love always," or "Yours forever." A knowledge of calligraphy is helpful to make your romantic love letter beautiful, but isn't required. Blot the ink and allow it to dry completely.
Get an envelope or make one from the same paper you used to write your romantic letter. If you make the envelope, use acid-free glue to seal it. Fold your romantic love letter and place it in the envelope. Light a candle and let some of the wax drip on the closure of the envelope. Press an object such as a decorative ring or stamp into the wax.