Don't think that your mats and die cuts need to be perfectly edged. Sometimes tearing the paper gives the photo a fun scrapbooking border. You can even get different looks from tearing paper. This is another way to add texture and dimension to your pages. This technique requires no tools and is very easy to do.
For a white edge, hold the paper and tear toward you.
For a non-white edge, tear away from you.
Keep in mind, this will only work if the paper/cardstock has a white core or white back side.
You can use water to draw the design to make tearing easier and use your thumb to make more intricate tears.
For added dimension of your torn scrapbook paper, chalk the edges.
You can roll the torn edges for an even more dimensional look.
Some uses for torn paper include: journal blocks, borders, flowers, mosaic with torn cardstock pieces, water, sand, mountains and photo mats.