Usually photographers work hard to avoid lens flare. It can be distracting, causing metering issues and introducing specular highlights. Sometimes, however, you can take advantage of it. For this technique to work, the sun needs to be near the edges of the frame, so check the forecast before you head out, and shoot early or late in the day when the sun is close to the horizon.
How to use lens flare to create atmospheric photos
1. Broaden your horizonsOn a sunny evening, find an open location, as for this technique to work the sun needs to be near the horizon, with a direct line of sight to your camera. To see when and where the sun will set in your location, visit www.suncalc.net
2. Get down lowIf the sun is still a little high, try getting down low. You can lay down in some tall grass to place the sun behind the model, and allow the grass to intrude in front of the lens to add spots of blurry highlights and enhance that intimate mood.
3. Watch the backgroundPlace the model between your camera and sun. The flare will wash over your model. Be aware of the background, too. You can get some really nice light there as well, and even have some fun with the bokeh.
4. Bounce the lightSet your camera to aperture-priority mode. If you expose for the sunlight, the model will be too dark. Set some positive exposure compensation to brighten the model, and bounce light in using a reflector so you have a balanced exposure.
5. Step asideIf the flare obscures your subject, move the light source to the edge of the frame by stepping to one side. You can also try moving the light of the sun behind your subject, but that's a bit more tricky. Usually it helps if you move around until you see it how you like it. A little lens flare is nice. Too much and you can't see anything.
I hope these tips could be of use. Now we just need some sunny days to test them out!