Journaling can be a therapeutic activity. Some journaling ideas include:
Positive Things Journal: Do you often find yourself thinking negative thoughts? Write periodically about positive things going on in your life and don't forget to review those positive things.
Memory Journal: Do you have special memories you don't want to forget or maybe memories of a loved one that passed away? Write about those memories in a journal.
Goal journal: Do you find yourself thinking about the future and the the goals you have for yourself? Write about the goals and the work you are doing to achieve those goals.