Lent is a time when we explore ways to deepen our prayer lives. A prayer journal is a good way to stay focused during prayer. I find this an especially helpful practice for teens who are trying to develop a deeper prayer life. But it is appropriate for all ages.
You may choose how often to write in your prayer journal, but it is best to keep to a set schedule.But it is perfectly acceptable to journal once a week or once a day or whatever fits your schedule. The important thing is to make it a habit. I started with once a day and then found it so helpful I eventually went to twice a day. In the morning I journal my Lectio Divina based on the gospel from the mass that day. In the evening I journal my Examen.
For your journal, you can use something with prompts to help you get started, like the Catholic Planner or Names of Jesus or The Examen Journal. Or you can just use a blank journal or any old notebook. Composition notebooks work well.
If your prayer journal does not have prompts, the daily mass readings are a good starting point. But you can also just journal about what is going on in your life. One thing I do in my writing, during my Examen, is thank God for three specific things every day. These can be an encounter with a friend, a beautiful experience in nature, or just some insight I am grateful for. I feel that gratitude is an essential part of my everyday life.
I think there are several benefits to keeping a prayer journal. As I mentioned at the start, it helps me stay focused during prayer. It is also good for me to be able to go back and read my previous entries. Sometimes that helps me see how God is moving me through my prayer. And I also find it has brought me into a deeper relationship with God. The act of sitting down with a cup of tea and my journal, getting comfortable, and planning on spending 15 minutes with God a couple of times of day has a real impact on me. I am truly spending some time in a real conversation with my Lord. I find myself pouring out my heart to my heavenly Father and gaining new insight for how to trust in Him.