Here are four simple barefoot techniques to get you started. Once you practice a bit you will discover the ease of using your feet, especially on the large leg and buttock muscles.
For further study see Barefoot Shiatsu by Yamamoto and McCarty.
1. Standing between the receiver's legs, facing outward with your back to the receiver, walk on the bottoms of both feet at the same time. Walk from arch to heel several times. Do not walk on the toes. Shift your weight from one side to the other. Your toes are on the floor; your heels do the pressing. This brings blood down from the upper body..
2. Walk up the calf with foot. Stand to the side of receiver. With your left foot press down on the Achilles tendon. Then, starting close to the heel, press the leg and calf muscles with the heel of your foot up to just below the knee. Never press on the knee! This relaxes and loosens up legs.
3. Change feet and press buttock with right foot. Then press the right thigh down to the knee. Repeat several times. Effective for relieving nervous tension.
Go to the receiver's left side and repeat same procedures on this side. (Press the Achilles tendon, then walk up the lower leg to the knee. Press the buttock and walk down the thigh to the knee.)
4. Stand between the receiver's legs, facing toward the head. Place the flat of your foot with the heel on the tailbone (coccyx) and gently press the muscles of this area. Stimulation here relaxes nerve centers in the body. Continue and press around the inner thighs of both legs.