For coming in to the lower beach with normal wind direction, especially with high tide, it's all about bearing off from a typical upwind course to a beam reach (perpendicular to wind direction) to get more board speed. Combining continuous power strokes with this fastest point of sail will generally give you enough momentum to make it at least halfway to the beach no problem.
For going out, it's all about semi-continuous power strokes at the top half of the window (don't let the kite get too low). Don't be afraid to fly the kite aggressively as needed to maintain continuous line tension. Otherwise your kite will be underpowered and will not stay at 12 or anywhere along the edge of the wind window by itself for very long (kite stall) Keep the kite moving at all times to generate at least a slight pull until you make it out to the wind line. With experience you will learn to recognize the feeling of impending slack lines and instinctively respond immediately to keep the kite in the air