When hiking hydration can be key. Without water your body has limited ability to function. In extreme conditions water can debilitate you and cloud your judgement much quicker than other things. Dehydration in extreme conditions can even kill you. Your body can only like approximately 3 days with no liquid/water intake. Even after 24 hours without water you will likely feel bad. After 48 hours without water you may feel cramps, light headed, and weak. Lack of water can even cause organ slow down and hallucinations.
Look out for leaves that form cups. Many leaves, particularly of low growing plants, form cups where water collects. This can be a great source of drinking water in an emergency.
On the Ground
Looking up from high perches look down to the ground for old stream beds. Some times dried stream beds can have areas that are moist or areas with a high water table. You can dig and have holes fill up with water in some cases. Sometime you can find depressions that have water remaining.
Water like people tends to like the path of least resistance. This means it often travels with gravity downhill. Look downward for lakes and areas where water is tracked and available in rock depressions.
Watch for grooves in rocks. Even though there is not running water where you are now. The grooves can show you the path of water so you can follow them and see where water went. You may find a puddle there. You may find a dried up lake or stream. If you dip a hole in a dry stream you may find that water seeps up and fills the hole (seepage well).
Find Little Animals
Look out for game trails. These are simply areas where animals cross and have worn down the vegetation. Typically the trails lead from an animals home to their feeding location to water. Remember wild animals need water too.
Look For Nests
The golden lake or other water source, perhaps smaller, is typically near animal nests. Animals tend to live near sources of food and water. Chances are if you find a nest then water is not far off.
Water and Scat
Look at for scat, poop. This shows that animals have traveled this area. you can often use the scat to retrace their path and perhaps find their drinking hole.
Examine Scat In the Sand Or Elsewhere
If you do see scat examine it. Examining the scat can help you in some cases see what the animal is eating. This can help you better understand what food sources may be available to you.
Look out into the horizon for green vegetation. Plants typically grow where there is water, even if the area around the water is rocky. Finding the green can potentially help you find water.
Sycamore trees usually grow near water. Finding the location of the sycamores can help signal you that water is near. These trees are easy to identify by their bark which looks like a white and tan camo pattern.