Supply a Focal Point A dry stack border is an excellent way to give a flower bed some presence and make it a focal point, particularly in an expansive landscape or a rural garden setting. Stacked two high, the boulders in this pretty purple and yellow garden arrangement give the flowers unexpected height. http://www.bhg.com/home-improvement/outdoor/retaining-walls/dry-stack-walls/?rb=Y#page=6
6 Steps to Make a Rain Garden: Rain gardens filter runoff and protect groundwater, especially after big rains. They also add unexpected beauty to low spots that tend to collect water and draw wildlife. Here's how to make a rain garden in your own landscape.
Control pests by planting these flowers for borders and drawing beneficial insects into your garden: Cornflower, Sweet Alyssum, Borage, Cup Plant, Anise Hyssop, Golden Marguerite, Fennel, Mountain Mints, Pussy Willows, Ornamental Grasses, Corn (article ends with LONG list of annuals and perennials)
plant combos, A few of my favorite plant combinations last summer around the golf course garden, You can't beat a classic "Gold Mound' Spirea with the coneflowers. The purple Heuchera in the foreground is 'Midnight Rose', which has pink splotches that are the same color as the coneflower. , Gardens Design