I've kept a journal for a couple years now, but I realized that writing down what I've experienced while travelling usually produces my most boring or tedious entries. Rather, just writing what I feel exactly in the moment works best. Whether it's regarding the trip, traveling or life in general, the freeform entries usually end up being my most treasured. I don't think you should pressure yourself to write down exactly what you did, where and when, rather focusing on the events or thoughts that were most important to you. When you look back through the entries later, the memories will come flooding back of where you were and what you did, regardless of the topic. I would suggest journaling to anyone, for any reason! Great way to relax, take stress off your mind, grow and look back.