If you do not have a creme brûlée torch, you can easily use a long grill lighter and use the flame of the lighter to make contact with the sugar to burn it into a crust. Alternatively, you can use the broiler method where you place the creme brûlée on to a sheet pan and place under a broiler on high until the sugar starts to melt and brown. Watch them carefully when doing this so they do not burn.