If you have a hard time starting, create a short outline. Maybe you decide to include three paragraphs with the first paragraph being a walk down memory lane, where you describe how thrilled you were to first start dating your spouse. Maybe you begin with a quote on anniversaries or love. The second paragraph can fast forward to the present where you let ’em know the qualities you love about him or her. And, the third paragraph could address your future together, e.g. looking forward to many more great memories, etc. An outline can help organize your thoughts.