What You Love About Them
Regularly record what you love about your partner. List the qualities and characteristics that attract you to him. These lists will help you remember why you love him during times when you're feeling disconnected. It will also record the progress of your relationship as you discover new things about him that you didn't know before. While every relationship has its ups and downs, don't write about your fights or your hurt feelings. It's best to forgive and move on rather than contemplating them.
Everybody remembers the big gifts and romantic weekends away, but it's the little sacrifices in daily life that show how a person loves you. Be sure to write down both the big events and the little things that your partner does for you on a weekly basis that you might otherwise forget. For example, you could describe that breakfast in bed you were served or the note of encouragement you found in your lunch at work.
Diaries are as much about looking back and remembering the past as they are about looking forward and hoping for the future. Write about the future plans you make together. As life is ever-changing, you may turn down a different path to the one you expected; however, you can look back at your previous plans in your diary and laugh over them. Make sure you always include the date and time of your entries; if you're a frequent traveler, you can also include the location.
A Surprise Gift
To encourage yourself to write in your love diary daily, address it to your partner, similar to a love letter. Writing to someone may be easier than just journaling your thoughts, and it gives your writing direction. You can write it to her future self if you intend to share the diary with her when you've completed it. You could also secretly keep the diary for a whole year and give it to your partner as an anniversary gift.