I saw this interesting tip on highfivehq.com about how to add an index to a paper notebook.
Now if you ever wanted to find a Chinese recipe you'd simply look at the index, locate the Chinese recipes label and look along the visible edge to find every single page which has been tagged as Chinese. Then it's simply a case of flicking to each page.
And of course, you’re not limited to one tag per page. You could tag a page 2 or 3 times. So if you jot down a chicken stir fry you could tag it as “Chicken” and “Chinese”. Now you can find all recipes by their cuisine and ingredient.