How to make tayammum in accordance with the sunnah?
A person who wants to make tayammum intends through his heart and tongue first, puts his hands with fingers wide open on the clean soil or a material made of soil, and then moves his hands forward. Then, he moves them backward. Then he shakes off the dust by clapping his hands. After that, he wipes the whole of his face by his two hands. Thus, the first touching is fulfilled.
Then, he touches the soil firmly with both of his hands, moves them first forward and then backward, and shakes off the dust. After that, he separates the thumb and the index finger of his left hand from the other three fingers; he wipes the outer side of his right hand up to the elbow. He wipes the inner side of his right hand and arm with the thumb and the index finger. Thus, the wiping of the right hand is completed.
The left hand is wiped similarly, and tayammum is completed.
As it is seen, while making tayammum, first the intention is uttered; then the hands touch the soil firmly twice; after the first touching, the face is wiped and after the second touching, the hands (first the right then the left hand) are wiped.