Easy way of finding floating islands is to use wooden platforms in a tower, like in the picture.

Next, when you are around abiut the mean of the hight you find floating islands (check the wiki on it here), build a bridge across either to the left or right to start with (see pic 2)

You will eventually find a floating island (see pic 3)

  • As of step one, making the tower.
  • As of step 2, it is best to have a depth metre.
  • As of step, you just keep walking and placing material and you will find an Island in the Sky. The bridge is below me.