I'm an old school miniatures gamer, none of those newfangled laser rangefinders or tape measures for me.
I made a dozen of these measuring sticks from 1/8" wood dowels a while back.
Construction is very simple, cut off a 16" section of dowel, then mark off the following measurements from one end - 8", 10", 12", and 14". Since OM uses 2" for it's (hex) ranges, this stick gives you easy measurements of all of the weapon ranges and vehicle movements.
Range 1 - 2"
Range 8 - 16"
I spray the whole stick white, then mask off the sections that need to stay white and spray the rest black. A shot of clear acrylic finishes the job.