something else i forgot to mention; mulch is also a quick easy method for erosion control, aside from helping to immensely conserve water. Eventually you would want shrubs, and groundcover between the shrubs, but do keep mulch surrounding large trees by at least a couple feet wide, and 4 to 6 inches thick. If you're not using drought tolerant plants, and you dont live in a rain forest, it will probably be a good idea to run irrigation. I'm trying to stop myself from writing a book here, but i will say that you should also make sure that you do have a thin layer of 100% humus just underneath the mulch, since when the mulch rots, it will actually use up nitrogen in the process, rather than supplying it. Plants love humus though; it gives them just about everything they need, which is important because youre planting them in heavy clay soil. Then again, you could always do a low maintenance rock garden, in which case you could easily go without irrigation

Also, if youre wanting to make an architectual statement: Forego the trees, make the berm very smooth and plant grass on it; or for color and texture, plant several different varieties of low growing ground cover, and maybe plant flowering azalia or pink knockout roses at the ridge, either in individual trimmed smooth globes or together in a hedge(better for soundproofing). And dont do the alternating plant thing, that's been done to death, and it doesnt look that good anyway; it's just a crappy way of adding variety while at the same time retaining strong lines, though in reality, it only produces both in a degraded form. It may have it's moments, but only in the right scenariao, and only when it's well done; most landscaping i see is like wearing a plaid flannel shirt as a fasion statement. Well, ive definately rambled a little beyond soundproofing here, but oh well

i already wrote it and i didnt want to delete it.