If your roses are blooming in clusters and won't be terribly missed outside, then clip far enough down to get the whole group. Cut about a 1/4 inch above a bud that is growing on the side, or direction, you want the plant to grow. Cut at an angle, not straight across. The new growth will sprout from the bud you cut above, so you can direct where you want the new growth to be. If cutting long stemmed roses, choose your bud to direct growth, or look for the first set of 5 leaves. Stop cutting in late summer and allow the plant to set hips and for the new growth to harden off to get ready for winter. If you don't want to take a whole cluster, then just cut out a few from the cluster and float them in a rose bowl, or use a very small vase or jar.