I started around five months but only about three or four times a week. I would put water in it at first. Now I put a combo of apple juice and water in it. She still hasn't mastered the technique of tilting it back. It's a work in progress. Good luck!
6 months about once a week. He didn't get it till about 10 months. I have only put water or formula in it. Pedi said no child was ever hurt by not having juice so he had never had it. It is mainly sugar anyway.
Started at 5 months. I've put 1/2 ounce breast milk or small amout of water. DS has yet to figure out how to get anything out. He mostly chews on the spout.
Re: When did you start a sippy cup?