Hadrat Jabir (Radi Allaahu Ta’ala Anhu) narrated that the Messenger of ALLAH (Sallallahu Alaihi Wa Sallam) said: “The chief thing in tayammum is to strike the hand on (clean) ground, once for the face and and again for both the hands upto the elbows. [Mustadrak]
The Prophet (Sallallahu Alaihi Wa Sallam) would not perform tayammum afresh for each Salaah. He did not even enjoin this either; he has made it a complete substitute for ablution. [Zadul Ma’ad]
The method of tayammum according to Imam Abu Hanifah Imam Malik and Imam Shafi (Mercy of ALLAH be on them) is to strike the hands twice on the (clean) ground, once for the face and again for both the hands upto the elbows. [Madarijum Nubuwah]
The ground on which tayammum becomes justified as a substitute for ablution, also justifies tayammum as a substitute for Ghusal (bath) (being fard) (obligatory in case of sexual emission). Tayammum for Ghusl (bath) is performed in the same manner as laid down for ablution. [Bahishti Zewar]
Tayummum can be performed on either of the following things: Clean soil and sand: Stone and lime; unglazed earthenware (whether baked or unbaked), baked and unbaked bricks walls of other baked and unbaked bricks, of stone or of lime (white washed) or of red chalk or of yellow earth.