MDMA has a very bitter taste to it, and features a "crystal" look to it. To give you an example, see this image:
http://upload.wikimedia.org/wikipedia/commons/2/21/MDMA_crystals.JPGNever drink alcohol before or while taking MDMA as both cause dehydration and can lead to serious problems. It is recommended to drink about 1L of water while on MDMA. You MUST keep track of the amount of water consumed as it is easy to drink too much and end up in the hospital.