Simple outdoor lighting

Sometimes it doesn't matter how good your camera is, if you don't know how to use it and your environment correctly then you won't be able to achieve good photographs. The biggest different between most regular photographs and the photographs taken by professionals is the way the lighting is handled. Just like a regular person, a lot of photographers use natural lighting, but there are tricks to how and when to use it.
The biggest problem that people have with using the sun as lighting is they don't understand that the sun causes shadows. These shadows look bad and they will single handedly ruin your photograph. When you photograph in direct light,  you often get harsh shadows and black marks under your subject's eyes (racoon eyes). To eliminate these shadows, simply photograph in a shadowy area. alleys and large walls allow a lot of shadow to cover your subject. All you have to do is stand your subject under the shade of a wall and... instant perfect lighting!

Direct sunlight.

Note the harsh shadows across her face

Under a shadowy wall.

Note no shadows on her face.

Another very important thing you need to consider when photographing outside is the position of the sun. If the sun is way over head like during noon, then you have really dark racoon eyes and all types of harsh shadows. Its also very hard for your subject to open their eyes during this time. Though you can take photographs at this time, its much more easier to wait until the "Golden Hour". This the time, two hours before sunset or sunrise, where the sun is directly behind you and your subject, and is lighting up their faces and its warm, yellow, bright, and it just looks beautiful.

A more advanced approach is to use fill lights. A fill light is the light that you create to literally fill in the shadows. A lot of times you can use reflectors to bounce the light from the sun onto a persons face, but there are also more natural things you can use. Some people set white sheets on the ground out of the camera's view so that it bounces light onto their subject, well the snow can also do the same thing. Its a very simple and natural fill light that just automatically bounces bright light onto your subject's face. There are other things you can use, such as light colored concrete floors and walls or water sources. Anything bright that can reflect light onto your subjects face is considered a fill light, rather its a technical piece of equipment or simply the light off a snow. Knowing little things like what type of things bounce light and what time to take photographs can make a huge difference in your photos. Little tips like these can take any regular photograph and change it into a professional photograph just like that.

Using Snow as a fill light

Oh! I almost forgot the most important tip of all. Overcast is a photographers best friend, because without the sun that means no shadows... at all! On overcasted days you can photograph anywhere without having to worry about racoon eyes. I take 99.99% of my photographs on overcast days because I myself am still having trouble manipulating direct light. So don't forget, overcast is the best lighting that the world has to offer you, so use it as much as humanly possible.