I drink about a cup or more of it daily, doing this with the EM mother culture would be very expensive... I plan of drinking more much in the future, as it is a good source of minerals, vitamins and antioxidants. Other than an improvement in digestion, I haven't noticed anything clearly different. I felt a lot of fatigue the first weak. I heard that one could experiment huge die-off symptoms many weeks and even months after having started EM.
Starting with like a tbsp as suggest Vinny sounds crazy to me, but I know that some people can be very prone to react to everything. I began with about a cup, and I'm still doing that.