I know a guy whose wife wanted to sell their house because the floors squeaked so much.
The Squeeeeek No More tools have been around for awhile. The one for carpeted floors is especially good, plus it’s easy to use.
Once you locate the joists under the carpeting, just drive in the special screws, then snap them off below the surface with the proprietary tool. It really is as easy as it looks.
Your customers will think you’re a miracle worker if you can make their floors quiet.