Since chances are that your phone was powered on when you dropped it in water, it is advisable to switch it off immediately after taking it out. After switching off the phone, start removing everything possible from the phone. Remove the battery, Sim cards, memory cards as well as any accessory.
Get an airtight container or a ziplock bag and fill it with uncooked rice. Place your phone inside the rice, shut the zip lock bag/container tight and keep it in a dry place. Leave the phone in the rice for at least 24 to 48 hours. Ideally, do not even try to take the phone out to check if it has started working or not. If there wasn't too much water damage, your phone should start working.
Please keep in mind that there is no guarantee that your phone will survive a dunking in water. There is only a 50% chance of your phone working again.
