Lots of good advice already. When I started riding last summer, I picked a straight, quiet stretch of street to learn. Didn't take long to master when I remembered to practice at least once or twice on each ride. (Rides were shorter then!) I'm right-handed and so I keep my right hand on the bars and grab the bottle with my left. Had to keep my hand close to the stem at first but now I have more "range. I don't think I could switch hands to do it but that would probably be a nice skill to have.