There is also a method I use where you apportion a page number to each of the polygons on each DDP and use a definition query [Definition Query>Page Definition Query} linked to the DDP data to only display labels and polygons for the exact page being displayed. This serves two functions:
1. you can draw the cut line on the page and display it/them when that specific page is activated
2. all labels and polygons for the overlapping ddp wont show on that page. For items that are split by the pages you will have to use the split tool along the cut line and assign, where split, to the next ddp in the sequence.