Extremely customizable, the Traveler’s Notebook takes a variety of inserts and refills in its leather cover. You can fit in monthly, weekly, and daily pages, along with folders, cases, and more. It adapts to whatever you want to use your planner for, whether it’s for bullet journaling, drawing, or scheduing.

Wirecutter picked it as the most customizable of the planners it reviewed:

The simple leather folio holds thin notebooks inside (secured with an elastic band), and you can invest in whatever notebook inserts fit your planning needs. It’s the only system we found that works for all types of planning. Artistic planners and memory keepers can embellish the weekly calendar or the blank insert that comes with the folio, and it also works for bullet journaling with the company’s grid paper or weekly grid calendar. For simple scheduling, fill it with the slim vertical weekly calendar or the monthly calendar and a lined notebook. And if you want to do a combination of these planning styles, you can mix the different inserts to create a completely personalized book.

Amazon and JetPens have the Traveler’s Notebook for around $47, and both also sell a wide range of inserts and kits to help you make the planner your own.