My latest sandal design.
Drill holes every 1/2" around sole, excluding toe area.
Spiral cord through holes.
Run long end through the spiral
Bring short end across base of the toes and pick up the last spiral before it goes down the core of the spiral.
Now you have two ends on opposite sides of the foot, and any number of places that you can pick up that cord between spirals. Lace as desired.