Fin_676 has some low cost good ideas, the rubber cush grips and foot pegs will improve vibes felt in the arm and hands. There is also an item called the "Bar Snake" which is a rubberized foam shock absorber that goes inide the bars that absorbs the vibes as well. Vpats idea works but is considerably more expensive as gearing changes with Belt Drive & Pulleys is not an easy thing.
Other helpful hints, do routine maintenance, check primary chain tension, use 85W Gear oil in the clutch/transcase (makes for smoother quieter gear engagement), make sure all motor mounts are tightened to specification, and engine ignition and fueling is even and smooth as possible.
While you are at it, add an EZ clutch kit, makes the clutch pull 30-40% easier, and tilt bars towards you to make it easier to turn handle bars lock to lock while seated properly and fit your hand and foot controls naturally. Some times the vibes seem worse because of improper fitment to the rider. And wear properly fitted boots and gloves helps.
