To avoid the flat look of finished embroidery and to have the three dimensional aspect,
without puckering and damage to the threads, you should iron embroidered garments
the following way:

1. Place a fluffy terry cloth towel on an ironing board.
   
2. Place the embroidery up-side down on the towel.
   
3. Press the iron on to the garment from the opposite side of the embroidery.