| It sounds like you are striking down on the string and slapping it against the frets before releasing the string. If that's the case, you should work on technique. If the string is rattling against frets after you pluck the string, you probably need some set-up work on your bass and some adjustment of your technique.
The direction of the string vibration would usually be at some slight angle to the fretboard, but depending on how long you let the note sustain, the string vibration plane changes.
I can't say I've seen any specific tutorial on this. You will probably be more comfortable if you work out your own method / style that eliminates the fret clacking.
__________________ For me, unlined maple fingerboard fretless necks are like cocaine to Charlie Sheen. |