Page 134 - Peter Randall "The Craft of the Knot.."

STEP 1 Make an Overhand Knot some distance from the end, so that
you leave enough running end to pass around the object and then back
to the Overhand.

STEP 2 Pass the running end back through the bottom of the Overhand
Knot.

Sometimes two Overhand Knots are tied next to each other in the

standing part. The running end is passed through the first one to provide
the grip and the second one to hold the end down.

Tie two Overhand Knots in the standing part, and tuck the running
end into the second one.

Like the Tautline Hitch, the Guy Line Hitch is meant for a support line