If you'd rather not adjust your recipes or buy more grain, you could try to address the crush issue directly. I saw about a 10% increase in my brewhouse efficiency when I bought my own mill and started crushing my own grain instead of using pre-crushed grain. My mill (Barley Crusher) gap is set to at 0.030.
This is my experience exactly. Brewed the same recipe with the Barley Crusher at 39 mil, then 30 mil, and went from 79% to 87%.