Do it as close the the fret wire as possible
Fender Classic Player 60s Strat
Washburn HB35
PRS Santana SE
Yamaha Pacifica 112MX
Vox AD30VT
Fender Champion 600
Dunlop wah
Danelectro Cool Cat fuzz
Dont have it on the fret metal, it sounds horrible. Move it back a little so its still relatively close to the fret but not too far back.
Fret it behind the fret (toward the nut/headstock, where the name of the guitar is)

so it would be like |.....F|
F meaning your finger, | meaning the fret. If it was 3 on a tab, behind the 3rd fret.
Quote by -BlackZeppelin-
Psh. I can can play fleshlight acoustically.