When shooting in hard light, shadows are your frenemies. Sometimes, they add something freaking gorgeous to the frame, sometimes they make someones face look like a Picasso. Hard light can cast weird shadows across someone's face/body if they aren't positioned just right and/or if you aren't doing anything to brighten up the shadows.
The easiest trick do balance that out is to shoot somewhere that has a naturally reflective surface (sand, snow, light rocks, etc.). The image below was shot on white sand dunes (which were pretty much a huge reflector) which means the hard light became a lot less hard (that's what she said). If you don't have those kinds of environments to shoot in, this is where a reflector can come into play. I pretty much never use one ( I don't even own one) but they can be handy if you're into this type of light.
This next bit is actually a little section of a Before / After blog post I wrote about editing for hard light (linked below) that I wanted to include because it's pretty important information to understand when shooting in hard light!
...LIGHT / EXPOSURE
Let’s start with what we should always focus on first, the light. The type of light you work with is one of the most influential factors on your editing. Editing for hard light and soft light is a completely different ball game. My typical images have soft light on both the subjects and the backgrounds. That’s very important to my style since my tends to have a softer (although still contrasty) feel. In the image to the right, I wanted to keep that softness in my subject while playing with harder light in the background. My setup was simple. The sun was coming through a small circular diffuser on her right (your left) which shaded the top half of her body. Other than that, I let the hard light takeover.
Exposing shots like this is the same as I’d expose anything else. I underexpose the brightest thing I want to keep detail in. Did you follow that? In this shot, I wanted to keep detail in the sky and the skin (I wanted to keep some blue sky) and since the sky was brighter, I underexposed that. That left the skin much darker, but that’s okay because we can bring that up in post without losing details. On the other hand, if I exposed for the skin, I would have kept details there but would have blown out the sky. When shooting digital, if you blow something out, it’s gone forever. It’s always best to err on the side of underexposure (unless you’re shooting film).
Tones! Woohoo! If you’ve shot in both, you may have already realized that one of the biggest differences in soft/hard light is saturation. If you look at a blade of grass in the shade, you’ll see a soft, peaceful green. Move it into the sun and it turns into a freaking neon blaze of green hell fire. Sun = Saturation. It’s just simple math.
Why does this matter? If I want to keep my images in hard and soft light consistent with each other, I have to understand how to manipulate that saturation. This is where the glorious HSL tool comes into play. If you don’t know where that is, it’s the super confusing looking patchwork of sliders under the Tone Curve in Lightroom. This panel allows you to manipulate three things about each specific color: the hue, saturation, and luminance. For example, I could change the blues in the image (make them a different color, add/kill saturation, or change the brightness of them) without affecting any other color in the frame. Pretty dang handy... (Read the rest of this article about editing for hard light here)