i write with a pencil...can erase it later. i've also started illustrating books by printing pics from wikimedia relevant to the topic im reading. i just glue

i write with a pencil...can erase it later. i've also started illustrating books by printing pics from wikimedia relevant to the topic im reading. i just glue them in. its more 'destructive' than the pencil underlining but it can be fun to come back to such a book later or after many years.