For my last trip to Aachen I used a real travelling sketchbook for the first time. Its a sturdy thing with about 40 pages of real mould made watercolorpaper, not one of those spiral bound I usually use fo doing thumbnails or little sketches to prepare actual paintings.
The drawings were completely different to the things I usually do and create some way more intense memories than the photos I took, so I highly recoomend to you to try out travelling with such a journey-book as well.
Best choose a sturdy, small and light book with good paper and some easy to use medium such as ball point pens or pencils. Watercolors can be a bit problematic because of the equipment and the time that is required to dry, so I colored the drawings at the evenings in my room. Dont be afraid to mess up a page, just take it easy and relax. Its like holidays for your drawing skills that are usually stressed at the drawingtable.