Rope the calf and get off your horse on the right side.
Run down the line holding the rope with your left hand. The calf should be facing you and your horse should be stepping back keeping tension on the line. Hold the rope the entire time you are running down the line. If you do not, and the calf moves sideways, you will be chasing it around. If you keep hold of the rope, you can just continue running down the line, even if it is not straight.
Flank the calf.
When you get to it, press your knees against its side. Stand over the calf with your stomach pressed against its back. Grab the calf by the flank while still holding the rope. Your hand will be next to its ear. Lift the calf off the ground by the flank and drop it on its side. This needs to happen fast. Calves are strong and the longer you wait or the slower you go, the more it is going to move.
Grab the calf by the near, front leg with your left hand as it hits the ground.
Put your piggin string around the leg just above its hoof with your right hand and pull the loop tight. Gather the calf's back legs under your right forearm and force them up and over its near, right front leg. Grab the tail of the piggin string -- attached to its front leg -- and loop it around the calf's three legs, three times. On the third loop, reach between the loop and the calves bound legs and pull the tail through the loop. Pull the tail hard so the knot tightens.