96 Lumina brakes problem

I have to change my front pads like twice a year because of vibration and shuttering even though the pads are not badly worn. I have turned or replaced the rotors several times over the years and am aware of the importance of properly tightening the lugs but nothing seems to help. I've also replaced the calipers in the past. Fortunately I have a lifetime warranty on the pads so the cost isn't painful but I'm sick of changing them. What am I missing?

Are you thoroughly cleaning the hub mounting surface and around the wheel studs, any rust there can cause this. I see Arizona so i guess rust is not an issue. Check for excess runout of the hub, you will need a dial indicator for this.

I am having the same problem with a 2000 Lunina. I have replaced the pads, rotors and guide pins about one year ago and the brakes are pulsing again. I use a torque wrench on the lugs also.
Looks like I am about to do the same thing again only this time I will check for the rust.
If there is anything else that causes this please let us know.