Hi there!
Let’s break down this image and see how I took it.
I asked the boy to stand around 5 feet away from the backdrop to avoid harsh shadows.
For this photo, I used a 50 mm f/1.2 lens at f/1.2, ISO 400, and a shutter speed of 1/500. I also had a large umbrella diffuser with a continuous light inside. The light was set in front of the boy, around 4 feet away from him, slightly higher than his eye level, and tilted down.
With toddlers, I usually let them be themselves and give simple prompts. Here, I asked him to start spinning his body and go wild, which he totally nailed.
Tip: 1/500s helps freeze the motion while still keeping the look soft at f/1.2. I would rather raise the ISO than end up with motion blur.
Tip 2: If your subject doesn’t understand your prompt, show them what you mean. Do a quick demo first, then let them copy you.