What qualities does a good love letter need to have?
Keep it short love.
Start the letter with a personal creative greeting.
Keep it cute love, make it a personal love letter from the heart.
Be ready to get vulnerable and show your true love feelings.
Explain why you love them and/or being with them.
Make people cry and/or smile.
Conversational/casual/personal in tone.
Close the letter warmly.
Take time to think if you send it, consider if it's the right gesture.