This is an easy way to attach cables below a desk. 3 different attachment points for different cable types since they are changed at different frequencies:

speaker/network (seldom) Power (med freq) USB (frequent) Made for 4mm wide zip ties. Smaller ones work as well.

TinkerCAD link: https://www.tinkercad.com/things/hdJtb1U9OhL
You could customize it there to use velco strips or similar.