Having great light is the key element to making a great image. For this reason; I spend a lot of time "searching for light." Having the right light is key because it will help create dimensionality and mood to an image. There are many times that I will see an interesting subject but it's not the right time for me to make the image. I don't believe that post processing or more expensive gear can replace great light. Everything that you do to make an image starts with the light!
Understanding how the time of day and weather can effect the light will greatly enhance your ability to make a spectacular image. The best times for taking photos are around sunrise and sunset. This is commonly know as the Golden Hours by photographers because it is typically when the light is the best. The light is warmer and more directional which helps add saturation and dimensionality. The shadows are longer and softer which makes things look more interesting as well. During mid day the sun is directly overhead and causes harsh flat light which results in washed out colors and the image will likely lack any real flare. This isn't to say that you can't make a great image during mid day but it certainly is more challenging.
Direction of Light
The angle and direction of the light is a big key as well. Knowing where the light is and how it will help or hurt an image is also very important. You can use it to highlight your subject like I did in the image below. I saw this tree when I first arrived at this location but it didn't stand out until I had been there for about an hour. Once the sun moved lower to the horizon and was just glowing on the tree alone I knew that was the time to capture the image.
Backlighting will cause your subject to become silhouetted but when it's used in the right way it can result in a great image. I used the setting sun to backlight the city skyline in this image. Sometimes a matter of minutes can completely change an image as well. About 2 minutes before and 2 minutes after this photo was taken the light was different and the rays from the sun were gone.
When I find a subject that I want to shoot I usually have the final image in my head but sometimes that changes when I finally take the shot. Knowing what I want to accomplish with the image; I will then spend some time to figure out where the light will be at certain times of the day so I know when I need to be there to get the shot that I want. I use an app called The Photographers Ephemeris to help with that. It's a great tool for seeing the direction of the sun at certain times of the day. You just plug in the location and adjust the time to see where the sun will be, it has some other nice features as well. Once I know when I need to be there to get the shot that I want; I will go there early to take photos a few minutes apart and see how the image changes with each shot. You may be surprised how many different images you can get of the same subject all within a short period of time. There will be times though that Mother Nature doesn't cooperate so patience is required. I've tried to get a shot several times before all of the stars aligned to get what I was hoping for.
Although this is somewhat brief I hope that you know a little bit more about how light can make or break an image. I only covered a couple of the ways that you can place the light to create an image but I recommend playing around with composition to see how you can use the light to create mood and interest. I am always looking when I'm out to find interesting locations and subjects to shoot. The key is paying attention to and looking at the light to know how to make it work for you. It really is about being at the right place at the right time but when you search for the light sometimes you can plan for the "right time."