Tutorial 46 - Painting an Energy Ball
More magic. This technique is a simple build up of layers, from dark red, through orange to yellow. Stay away from getting too bright with the yellow until the end, then add some subtle hot areas. 

Use the selection tool to make curvy edges, apply some orange and yellow, deselect and smudge a little here and there. Play around with the layer modes. 

The trick here is to keep things subtle. It's very easy to get carried away with layer modes, over detailing and getting too hot too early.