I like to gage fluid intake by urine color. If your urine looks like apple juice then it's very likely you need more fluids. Aim for a light lemonade color instead of a darker color. Keep in mind that some supplements (e.g.: B multivitamin) or medications can often alter this color if you take them regularly. Need a reminder? There are many free smartphone applications which remind us throughout the day to drink water. Try them and see if this help should you need that extra push.