More recently I've been focusing on Gondor in flames, here's a break from the action:
As shown in Battle games in middle-earth 27.
In case you don't have an issue here's the rough process:
Cut out a piece of card 12"/30cm by 2"/5cm, although I've used 2"/5cm by 6"/14cm as my sheet of card wasn't big enough
Cut out a 1"/2cm by 1"/2cm by 12"/30cm section of polystyrene (triangular prism)
Glue to the front of the card base
At this point the magazine made the fire-step, but I had already continued with the fence spikes at this point :S
Cut barbecue skewers into 5cm and 3cm lengths and glue against the earthworks
Cut out a piece of foam board 1"/2cm by 12"/30cm and glue behind the wooden spikes, then glue a thin scored sheet of balsa wood of similar size above it to look like boarding.
My fire-step was made of lots of matchsticks
Glue halved cocktail sticks to the front of the earthworks, around 2 per inch of palisade.
Giving a total of 36 inches of fortified ground. I'm quite pleased with the result, although I was surprised that not many other attempts are shown at all on the blog-o-sphere.
If you know of a website or blog that has done something similar, I'd be pleased to look at it.
Now all that's left is to paint this piece, the magazine doesn't suggest a paint scheme so I'll just wing it :)