Step 8
Delete the rest of the body in the ‘model mask’ layer, leaving only the hand, then go Layer > Layer Styles, and select Color Overlay. Pick an orange, change the blending mode to Linear Dodge, and set the opacity to 88%. Use an orange for the colour and change the Blend Mode to Linear Dodge (Add). Change the layer’s blending mode to Color Dodge.

Step 9
Add another layer on top of the others and name it ‘smoke’. Go to Filter > Render > Clouds. Again make sure you have black and white for the background and foreground colours. Change the blending mode to Color Dodge and with the Eraser tool (E) set to a big, soft brush, delete most of the areas of the layer, leaving only the part close to the arm that you’re going to set on fire.

Step 10
Select Layer > New Fill Layer > Solid Color, then click on the layer to open the Layer Style dialog box. Select Gradient Overlay and change the blending mode to Overlay. For the colours, use orange and a very dark orange; set the style to Radial and keep the scale at 100%. Move the gradient so the lighter part is on top of the model’s hand.