Extending the hair with a piece of cloth.
Question

                The Prophet 
 (peace and blessings of
      Allaah be upon him) said: “Allaah has cursed the one who makes hair extensions and
      the one who has this done.” Does this include the pieces of cloth or ribbon which
      young girls put in their hair and which may be made in the shape of a rose or whatever for
      decoration, or the necklace of white ribbon which some of them wear? I have young
      daughters, and I am afraid of them falling into sin.
Praise be to Allah.This hadeeth was reported by al-Bukhaari, Muslim 
  and others. What it refers to is those who add hair extensions taken from the 
  hair of other people, and the women who ask to have this done. The reason why 
  this is forbidden is that it is false adornment which could be used to deceive 
  or cheat others in matters of marriage and so on. As al-Bukhaari narrates from 
  Mu’aawiyah, the Prophet  (peace and blessings 
  of Allaah be upon him) called this falsehood. If we understand the hadeeth and 
  the wisdom behind this prohibition, we will see that it does not include the 
  wearing of ribbons and flower-shaped decorations by young girls. As long as 
  wearing ribbons on the braids or necklaces made of white ribbon are not customs 
  that belong exclusively to the kuffaar, there is nothing wrong with doing these 
  things, because the principle is that everything is allowed unless it is expressly 
  forbidden. But the girls who do these things should cover these decorations 
  in front of people who are not their mahrams (blood relatives whom they are 
  permanently forbidden to marry), if they are at the age where covering themselves 
  is obligatory. But everything that is done exclusively by the kuffaar is haraam, 
  because the Prophet  (peace and blessings of Allaah 
  be upon him) forbade us to imitate or resemble them.