The first two seasons of Star Trek: the Next Generation were admittedly uneven, but in my opinion, the Borg have never been scarier than in their very first appearance in the season 2 episode, “Q-Who?” At that point they had no interest in assimilating humans. No “resistance is futile”. They were a mindless hive mind, destroying civilizations and taking their technology. This was the first time our beloved USS Enterprise and crew were utterly helpless and outmatched by a foe, only saved by the intervention of Q.
Fiberglass and latex
For this costume (which I think I built after “The Best of Both Worlds” two-parter) there were some decent photos of Borg costumes available in magazines like Starlog and Cinefantastique. I would draw features from various drones.
I sculpted the major “organic” pieces in clay and produced fiberglass or plaster molds, depending on that was being cast. I sculpted and cast multiple attachment modules for the copious amounts of split loom I was using for the tubing.
I detailed my fiberglass-cast arm sculpt with various model parts and old videotape heads I scavenged from KGUN-TV. I wired a model tank motor and gearbox to the rotating “tool” at the end of the arm, controlled by a switch inside the arm. I also had little manual actuators inside the arm I could pull with my fingers to make the side parts oscillate up and down. No servos here.
I made a latex boot to fit over my right shoe.
My first pass of the costume had a fiberglass head cap and neck piece and not much on the chest except some small modules and split loom. I used yucky white clown makeup to create the Borg pallor, mustache and all.
Some time later I made some upgrades. I re-did the head cap and neck piece in latex. I built a large chest and back piece to cover more of my skinny frame. I also sewed a new leotard (that showed every inch of sweat) to replace my original one that was very wrinkly.