Greetings! A while back, sometime around 4th edition 40K, I had built up a Tyranid force and focused mostly on Genestealers and Gaunts. It was a purely recreational force. Eventually, I had made several bits of terrain based mostly on what I could scrounge from the box set Battle for Macrage. I did make a few spires but modeled them on a more H.R.Giger's style and the Thralls of the Fallen Empires set from Magic: the Gathering.. Here's an older post with picks of the spires and the old Hive Fleet. There were also breeding pits, hive nodes (built up versions of those found in the box set) and even some mutated vegetation and overrun ruins. A lot of it got recommissioned into later terrain except for the spires which I put up for sale as they were along with all the Tyranid army since I had begun to play Tau more often.
Now that 6th edition has arrived, and terrain has begun to take on a bit more significance, I've dove back into making Tyranid terrain. To start off the adventure, I've made some spires. These are two different building techniques. One uses plaster cloth over foam and the other is built up from card stock. Both are detailed in hot glue. I decided to paint them in Hive Fleet Behemoth's color scheme.