First of all, my green juice today contains vegetable, herb and fruit. Put two stalks of celery, a fist full of parsley, one kiwi with the skin removed and a little water in the blender and blend. Finally, pour into a glass and drink! You can add more water if necessary.
Note that if you have sufficient iron levels from other foods you may not need to drink green juice. Once I felt well again, I usually now have a juice once a week but I vary the contents of the drink.