I needed a better grip on a jeweler's screwdriver, so made this push-on handle. It's a parametric OpenSCAD design, so easy to tweak until the fit is right.
Run through OpenSCAD and adjust the parameters provided:
bodyHeight = 40;
screwdriverDiameter = 5.7;
outsideDiameter = 20;
roundness = 0.6; // Smaller rounds the ends more
baseDiameter = 3;
The small base is there so it can be printed vertically. Rough up the surface with sandpaper for a better grip.