I haven't seen anything but a gimbal or glidecam/flycam provide sufficient stability for an un-stabilized camera body before. The latter is still pretty cheap. Or, buy a used gimbal.
Also, wider lenses will help the image appear to be more stabilized. When you're starting out, you may want to to use a lens between 10mm and 23mm. For long walking shots on a gimbal, I use as 12mm because anything above that and I notice bouncing in my walking steps.