I suppose you could say I keep a prayer journal. I started last summer, but it didn’t really work out too well. (That was my fault, because I wasn’t really praying much, just not talking to God and letting Him speak to me). I think my problem was that I treated it as a regular journal, except I talked about more spiritual things.
Then I helped put on a peer to peer retreat, and I’ve been writing to God almost every day (I think I missed 2 days or something in the last couple months). I just talk to Him, telling Him about my day, my struggles, thanking Him, and writing generally random things about my life. I usually write at night, because it’s quiet and that works for me, but sometimes I’ll pick it up during the day. Honestly, I would say just start writing to God and see how it goes. It might be hard to do it every day, like I said it took a retreat to get me going, but just do what you can. See what works for you, because I know that everyone’s relationship with God is different. A lot of times I end up doing really different things with it too. I’ll listen to music, write little spiritual stories, but mostly just talk to God. Sometimes I read back over it and usually I get overwhelmed with gratitude because of either how much He’s helped me, or for the blessing I recieved but didn’t see back then.
I don’t know if that helps. Lately I’ve had trouble putting my thoughts into words when talking to other people, so sorry if that was confusing. My advice is to just start and not worry about where it’s going right now, just to see where God leads you.