Behind the toes, measure over (not fully around paw).

Start at the upper ridge near the entry of the paw, go down between toes to where the toes touch the floor (for center toe strap).

Measure around the ankle while wearing the paw.

Measure straight across the widest part of the paw (usually across toes).

Measure straight across the full length of the paw.

Take a picture of the bottom side of the paw, try to capture it flat and straight on (used to define the shape of the sandal).