Pardon the horrible Sir Mix-A-Lot themed title. Let's talk about back light. Rim light. Whatever you call it, it's an element of composition that I've been paying a lot more attention to lately. Instead of just considering whether the subject's face is well lit, I often look for amazing rim light and go from there, either using my flash or a reflector to bump up the light in the subject's face. It's tricky though, because too strong back light can make an image really hazy (and not always in a good way) or it can throw off your auto focus. So a lot depends on how you position your subject and yourself. I'm not 100% successful using it but I really like the added dimension it brings to a portrait when it works out. I'm going to keep at it.
Morning sunlight was coming through the trees and bushes to the right, so the light was nicely diffused.
Strong evening light was coming in from behind the subjects, so I used my flash set very low to fill in their faces. I was laying on the ground to shoot this, 24mm lens probably around f/4.