Lake Forest took its name from the eucalyptus groves and man-made lakes of the development that started it, and on a warm summer evening those tall trees still throw long shadows and drop curls of bark across lawns in what used to be called El Toro. OceanScape Design Inc. offers landscape design and lawn care in this Orange County city, where Serrano Creek winds through a greenbelt and the red sandstone of Whiting Ranch rises along the foothill edge. A design that suits the slope and the sun, then grass kept dense with the margins neat, lets a yard settle into the land as if it had always been there. When the evening breeze stirs the eucalyptus and the heat eases off the pavement, the garden simply looks right. That calm sense of belonging is what OceanScape Design Inc. works toward in Lake Forest yards.