i do brakes for a living and have never had a noise comeback. this is what i do to eliminate noise.
-use a sander and polish the complete hub surface and and flat mounting points on the spindle as well as bracket. (i sand till its a mirror finish).
-i apply a thin coat of NAPA Syl-Glide onto the face and outside of the hub as well as to and flat points i used the sander on.
-the brackets i will fully disassemble and clean with aqueous cleaner and then dry with brake cleaner and new lint free paper towels. and slide pins get cleaned and coated with Syl-Glide. i put them in and move them back and forth making sure theres no binding whatsoever.
-i apply a SMALL dab of anti-seize onto the bolts and torque them to factory specs.
-on the pads i apply Syl-Glide to any point on the bracket they contact, note only use a small amount and dont get it on the face of the pad or the rotor.
-i throw away any backing plates that were with the old pads because my supplier sends out new ones.
-the rotor gets cleaned with warm water and clean lint free paper towel, then get sprayed with brake cleaner
-once everything is assembled i go through with the torque wrench again and retorque everything.
-i then follow Brembo's brake-in procedure for the 00R kit on every car i od no matter the brand
-the car comes back into the shop and i recheck the torque again on every fastener, then the wheel gets properly torqued again
thats what i do, and im basically flat rate. i would rather take longer the first time and never have a comeback then blast through a job and redo it a few weeks later. btw any time i do brake work i do a full fluid flush with a Vacula on the whole system, then hand bleed each corner until the pedal is to my liking.
also, where i work i only let the sales people use the premium parts. a lot of times you get the option of a cheap part and premium. i also will refuse to do a job if the customer wants me to use cheap stuff or do just half the job. the only time i let customers give me stuff is if they want me to use a special brake fluid, like Valvoline synthetic.