I tried Tamiya's zimmerit texturing tool, but was not satisfied with it. I found using a mini screw-driver, or the largest screw-driver from a jewellers set better. And both can be found in dollar stores. A strong sewing needle, such as an embroidering needle ( also very cheap) can be used in a pin-vise to make a very fine scriber.

I also use the cheap dollar store sewing needles as super glue applicators, using the various sizes for different jobs. And, the craft sticks (popsicle sticks) make great paint stirrers. :-)