You can absolutely create professional-level portraits using nothing but a single key light, but once you move into multi-light setups, you get a bit more creative and technical control over the final image. One of the first ways to do this is by adding a fill light, and this excellent video tutorial will show you what it is and how it can be used to create better portraits.
Portraits
How to Run a Successful Portrait Session

Running a successful portrait session can be a daunting task, especially for photographers who are new to working in a studio. The myriad of options can easily become overwhelming. There are endless choices for light modifiers, backdrops, props, clothing, poses, and all the rest, but I have found that having a consistent plan and process is the key to success.
What Focal Length Should You Use for Portrait Photography?

In order to create great portraits, you need to have a lot of great components: lighting, composition, as well as camera and lens choice. Deciding what focal length to use for portraiture can be difficult, so in this article, I will make a few suggestions on lenses you should use for your next portrait photoshoot.
Why Mistakes Are Such an Important Part of the Photography Process

When you are new to photography, it can feel like professionals know exactly what they want and how to achieve it, but that is how social media can be quite misleading. The truth is that professionals make mistakes all the time; in fact, they embrace them. This excellent video tutorial will take you behind the scenes of a photographer’s portrait lighting process and show you how mistakes can lead you to a great final image.
5 Helpful Tips for Posing Couples

Posing is something a lot of photographers struggle with, particularly since it is not something you can just learn objective values for like you can with camera settings. If that is something you are struggling with a bit, check out this fantastic video tutorial that will show you five tips for posing couples.