If one big wall won't do, several low walls with level terraces between may be the right solution. Consider paving a level to create a patio and a comfy seating area. An inviting midslope patio is a great place to sit and survey the rest of your garden.
Pam Reddoch, an avid West Knoxville gardener and hiker, has landscaped the back of her hillside yard with tiered decks water features. Stone steps and paths meander around the slope and through the plants.