2c-e is not habit-forming, infact you can't do it until you rebuild your tolerance which takes 5 days. 2c-E is a very dark, yet colorful trip, a lot of de-personalization. I would try 2c-i before doing 2c-e. 2c-e have very little side effects afterwards.

As a starter dose, I would do 12mg, the difference between 4mg is double the intensity of the trip.