This year I saw a large silk flame prop at spirithalloween, and got an idea to use it with the foam insulation coals as one piece. Turned out even better than I thought it would!
You will need:
2 or 3 aerosol cans of great-stuff insulation
5M of orange LED strip with power supply
large silk flame prop
white spray paint (optional)
1M red led strip with controller and remote (optional)
Start with a piece of plywood as a base, put the silk flame in the center. Build walls around the silk flame to keep it separate from the foam, and allow enough room around it for airflow. Add diagonal strips of wood to support LED strips and foam. Make sure the wiring passes through the wall so you can plug it in. TEST it to be sure it gets enough air.
Wrap the 5M orange LED strips around the diagonal pieces of wood, (secure them in place with string or clear tape) and glue your power supply to the base. Route the power cord alongside the cord from the silk flame.
Step 3 (optional)
The silk flame has leds that are yellow, no flickering effect, so...
Remove the fabric from the silk flame, put masking tape on the yellow leds and spray paint the top end of the plastic box. (white paint reflects more light than black plastic). Mount the 1M red leds inside the flame box facing up or inwards (to illuminate the fabric). Set the light controller to flash on and off quickly. Secure and route all wiring, with the remote sensor located where the foam wont get in the way. TEST IT
Here's the fun part! Spray the foam insulation to make all of your coals
After the foam has cured, collect branches and sticks to pile around your fire to finish the effect