This may be old hat to many of you folks, but I thought that I would throw it out there. I typically use a bit of graphite to lubricate the nut slots in my Strat. Last week, I used a bit of vaseline in the nut slots and the underside of the string tree. WOW. I was pretty surprised when jamming yesterday. I did not have to do my usual frequent retunings. My Strat tuning pretty much stayed put.