To complement commercially available soft sanding sticks, I make solid sanding sticks in a variety of grits. I find them useful to sand flat spots when removing ejector-pin marks, mold seams, etc.
What you need is: a few popsicle sticks; various grits of wet-or-dry sandpaper (available from auto parts and hardware/home improvement stores); contact cement (the kind that comes in a jar with a brush is better); and medium-size (1¼" wide) binder clips.
Cut a strip of sandpaper wider and slightly longer than half the length of a popsicle stick. Draw a line across the popsicle stick at the halfway point and write the grit grade on one end. Apply a film of contact cement on the other half. Lay the sandpaper strip from the line past the tip of the stick. Sandwich the sandpaper stick with another popsicle stick and clamp them with binder clips. After 24 hours, remove the clips and trim the excess sandpaper away from the popsicle stick. Now you have a sanding stick for whenever you need to use something stiffer than soft sanding sticks or metal files.
Tip submitted by:
William P. Hicks IIDecatur, Georgia