The current VEX Extension Cable Retaining Clips are a HUGE improvement over zip ties/electrical tape, but I think they still have room for improvement.
While using the aforementioned clips, we have had cases where (with older, somewhat worn wires) the wires and pins pull right out of their housing, let alone the retaining clips.
As such, I think a second version of these clips ought to route the wires through at a right angle, helping to mitigate this problem. My inspiration for this idea comes from the clips listed here. In other words, I think a fusion of the current VEX clips and the linked clips would be good.