When writing a love letter, you usually use a blue pen or a black ink pen. It's best not to write love letters with pencils or ballpoint pens, let alone with red ink, because in some people's minds, writing letters with red pen means "breaking off diplomatic relations". The handwriting should be neat, the font should be correct and clear, and don't scribble to make people guess riddles. At the same time, we should also pay attention to the use of punctuation marks to avoid misunderstanding.