First was rear suspension was shot, fixed with new shocks and the headshakes were gone. The prevailing advice at that time was that the shake at the front end is usually traced back to a problem at the rear.
Next, and much more recently, it was cured with a front suspension oil change. But my most recent CB still tends to get shaky on the front when I fit my two-lid topbox on the rentec rear rack and stow any more than about 1kg of gear within. Again, I think back to the advice I received years ago and that the front can be affected by what's happening at the rear.
Then there's tyre pressures. A likely and cheap to fix culprit.