1. Keep your journal small, but durable
You don't have to have a brand new fancy notebook, but it should be durable enough to last quite awhile. The last thing you want is your notebook falling apart at the spine halfway through your trip.
Figure out what size notebook will work best for your needs. If you want to record experiences throughout the day, it will need to be small enough to fit in your bag or pocket. But if your notebook is going to stay in your hotel room most of the time, you can opt for a slightly bigger size. Still, you don't want your notebook to be too cumbersome while packing. You also want to have enough room to write or draw in it — so a teeny tiny pocket notebook might not be the best fit.
2. Make sure it's organized
Organization is important for your trip and beyond. Don't worry about numbering all of the pages, unless you want a detailed table of contents. Your organization system can be as simple as dating each entry before you write or draw. You could also jot down your location as you write each entry. If you plan on sketching a lot, you could divide your notebook into two sections: one for writing and one for drawing. Or if you're taking a road trip or visiting several different cities, you could divide your notebook up based on location.
It's really all up to you, but make sure your organizational system makes it clear what entries you wrote when. This is important for the future whenever you decide to look back at your journal.
3. Set a daily time for journaling
You've decided to keep a travel journal, but keeping up with it is the most difficult part. Some days, you'll probably be caught up in everything you're seeing and experiencing and forget to write your memories down. The best way to avoid making this a habit is to schedule in time to journal. Even if you have a packed itinerary, blocking out just 15 minutes before bed to record your day is totally worth it. If you want to journal on the go, schedule that time into your day as well. This way, you'll never feel rushed — which is never a good thing while on vacation.
4. Don't hold back in your entries
When posting on social media, you might feel the need to edit yourself or censor your emotions. That's because you're sharing publicly. The beauty of a journal is that (unless you choose otherwise) it will be completely private. No one has to see your journal but you. Because of this, you can write down your thoughts completely unfettered. Don't hold back. Write down all of your experiences and emotions. If you hated something, say so. If you felt sad or moved, write it down. This is the best way to help you remember your trip when you read your journal in the future.