Page 30 - Peter Randall "The Craft of the Knot.."

STEP 2 Tighten the knot by pulling on the strands.

This knot is rarely tied by itself, unless you keep on tying this knot to
cover a cylindrical object.

DOUBLE OVERHAND KNOT

This knot is the first in the multiple overhand series. It starts with a
Simple Overhand Knot, and then the running end is passed through the
crossing turn a second time, making the belly-and-spine appearance you
see in Step 1.

STEP 1 Lay down the rope with the running end facing left. Move it

down and twist to make the belly, bringing it up over the right side of
the standing part.

STEP 2 Run the running end up and under the standing part, making
two overhand loops.