Single basics are standing in a posture and moving in a pattern, such as circles and figure eights repeatedly. A posture is established by foot position, primarily. The movement entails paying attention to specific methods of moving—where to move from, how to initiate a move, how fast, how slow. Key to it is attention to changing directions and where to sustain focus. If you know what do, then you have a better chance of accomplishing the task. So begin somewhere with a task in mind. Simpler tasks are easier. Focus on one movement.
Through single basic practice you train for looseness, connectivity, endurance, precision, strength, balance and awareness. Start big if you want, but small and effortless is best for most. It feels more in control and complete. By this I mean working on the outside is not as effective as working on the inside. The internal emerges, rather than the outside acting separately from the internal.