A page you can read a week later
Write the date and a recognizable place in the same position every time. Then leave one blank line before the first observation. That small gap gives you room to add a street name or cross-reference later without burying the original note.
Recording a texture with a pencil
Use the side of a soft pencil and let the paper describe the raised parts of a surface. Keep pressure light near tears or loose material. A separate sketch of the outline helps a rubbing make sense after it has been filed away.
An index built from repeated places
Choose a short name for places you return to and keep using it. Record observations in time order. A separate index can gather scattered pages under a place name without rewriting the entries or hiding the order in which they were made.