The sun is the cheapest form of light available, you just have to play by its rules. The best time use it will be during the golden hours, which would be just after it has risen or just before it sets. The light during this time is very soft and helps improve the overall image.
Contrast this with a high noon sun. During this time, you will get very harsh shadows on the face because the sun is directly above you. These sorts of photos don’t tend to make the subject look very flattering and really tend to flatten the image. During this time, I’d recommend either using flash or finding a shaded area or both.
Don’t forget all the natural tricks nature does to manipulate the sun light. For example, you can eclipse the sun with your subject and have a bright shining light behind them. You have just have to be willing to find the correct angle to that. You can also do the same thing with trees and other things. Just be sure the object is between you and the sun and there is enough space for the light to shine around the object being used to eclipse the sun.