I'll often copy sections of a map into my notebook. Either my geology field book, or my everyday pocket notebook. These maps aren't very big, and don't have much detail (at least not in the woods, in cities they can more detailed then a road atlas or internet map) but they familiarize me with the map I'm copying and they provide a useful back up to a full sized map. I'll start out by drawing in the grid lines, and use those as a guide for drawing in major features: roads, rivers, structures and major hill tops and a few contours. I'll draw them with different colors of bic pens I've cut down to 4" lengths, black, red and blue. These maps don't give a perfect representation, but they can help you find your position if you're slightly lost, or give you a panic azimuth if you're really lost. "I don't know where I'm at, but I know I'm north of this road and I can't be more then a few kilometers from it." In a foreign city, they also let you reference a map with out looking like a tourist.

The other thing I'll do if I'm covering a lot of a map or multiple map sheets is fold, cut and glue them to make a sort of book. This is kind of difficult to describe with out pictures. The first step is to cut the boarders off the map exactly so you're left with a rectangle that has nothing but map on it. Then you fold the map into a 'W' shape, with three vertical folds and glue the middle of the 'W' together with a glue stick to make a 'T' shape. Effectively reducing the white space on the back of the map by half and creating three pages. Then, you take an exacto knife and ruler and split the middle page in half horizontally. Finally, you fold the map in half horizontally in line with that cut.

You now have a map that easily folds up into a package 1/8 of the map's size and unfolds like a multi-dimensional book to show either 1/4 or 1/2 of the map sheet. To move around the map you just turn the page. You can even glue multiple map sheets together.