Being able to ask for a drink is so important - especially as summer is approaching. We're all fab parents so we tend to anticipate our little one being thirsty and just provide the water, but if you take a moment to SAY-SIGN-DO, you can teach your little one to ask for water by themselves.
It only takes a second. Before you hand over water - pause. Hold the water in your hands by your face. Your child probably wants the water so they'll look to you face (if you held it by your side they'd look at your body and would miss what your mouth and signing hand are doing). Say "water" or "water please" and sign 'water'. Wait a second to give your child a chance to do the same. If they don't - that's fine - give them water. You should never withhold water! Just create a brief moment where they're tempted to sign back to get the water quicker.
Support your baby to respond at their level. A young baby might make eye contact or wave their arms. They might babble in your direction. An older baby might reach out or attempt the sign by hitting their face. A toddler may say "water" and/or sign. All responses are communication and should be celebrated! Your little one is communicating that they want water, instead of you just providing it. The more you model - the better they'll get at communicating.