You can "rock root" roses, holly, magnolia, large and small leaf rhododendron and many other shrubs, especially those with low or flexible branches. This propagation technique is more widely known as stem layering. It simply entails covering a branch with soil until it develops enough roots to survive on its own. I use a rock placed over the soil to help keep the branch buried—hence, rock rooting. 

• Find a low-slung branch on a plant you want to propagate.
• Strip the leaves from the portion of the stem that will be buried. Keep leaves at the tip of the stem, which will remain above ground and serve as the basis for your finished new plant.
• Injure the bottom part of the de-leafed section just slightly with a pocketknife in two or three places, taking care not to cut through it. (I've never gotten an adequate explanation for why injuring a stem speeds up rooting, and I've had success skipping this step.)
• Put the de-leafed portion of the stem in a trench about its same length and about two or three inches deep.
• Cover this section with rich soil containing a little vermiculite, leaving a slight depression above the trench to better allow water to collect.
• Put a heavy rock or brick over the springiest part of the stem to keep it in place. You can place a second rock to prop up the stem where it exits the trench. This will direct the new plant into a vertical growth pattern.

Under ideal conditions, a branch layered in late spring will be well rooted by the end of September, although the process can take up to a year. Test it by removing the rocks and tugging on what will be the new plant. If there's resistance it likely has a well-formed root mass. You can now clip behind the rooted portion of stem (the side closest to the mother plant) to remove the clone—that’s technically what it is. Then transplant it to wherever you want it to grow.