DIY Photography blog interviewed VanAlthuis on his techniques:
The tool used was based on Zach [Smidt]’s fire technique, which involves wrapping and stapling a 100% cotton t-shirt around a wooden dowel. The shirt is then soaked in BBQ fluid and then lit. I used this technique on my own wing-shaped tool to get the effect and look that I wanted.
It is important that your shirt is 100% cotton, any kind of blended fabrics can melt and cause burns. If you attempt this, PLEASE take all the proper precautions and be safe. I recommend wearing flame resistant gloves and shooting at a place with plenty of water nearby
Once we had all of our gear set up and ready to go, we had to set up the composition. In order to give [model Faith Leuzarder] the illusion of her “flying” I had her pose on a small step stool. I also took separate shots of just the background and then separate shots of her feet. This allowed me to remove the step stool in Photoshop and create the “flying” pose.
For this shot, I brought my favorite shot of the Phoenix wings into Photoshop, including the shot of the background, and the extra shots of my model’s feet for layer work. Using different layering techniques, masks, clone stamping, and blending modes, I removed the step ladder and replaced it with the background. Then I composited her feet back into the image in order to create the illusion of her “flying” above the ground.