1. clean/wash your windshield
2. Clay bar your windshield
3. Wipe your windshield to remove clay bar lubricant
4. (Optional) apply Rain-X to freshly clay bared windshield
If the wipers still shutter, the issue may be with the wiper blade as there is a dragging friction/defect causing the blade to skip/jump and new blades may be necessary.
DO NOT buy those Rain-X wipers as they are junk. Yes, they apply the Rain-X solution to the windshield on the first uses of the blade in rainy weather, but after the first month, they perform no better than any other standard wiper. You are better off applying the Rain-X solution to the windshield by hand as the effects last longer.
With Rain-X on the windshield, you should not have to use your wipers unless the rain is extremely heavy and visibility is greatly reduced.
In standard or light rain, I've rarely used the wipers with a Rain-X'd windshield as the water just flies off. My experience, YMMV.