My uncle told me to always pre-fill screw holes before hanging a TV mount
He said to mix a little joint compound with water and pack it into the drywall holes before driving the screws, claiming it would give a stronger hold. I tried it on a job in Tempe last week where the client wanted a 65-inch TV mounted. After letting the compound dry for about 2 hours, I drove the screws in. The mount felt rock solid, and I didn't have any of that slight wiggle or spin-out I sometimes get. Has anyone else used this trick for heavy wall mounts, or do you stick with just anchors?