Engraving with Foredom flexible shaft

Hi

Can anyone direct me to a source that gives good instruction on how
to etch and engrave metal with a flexible shaft tool and a diomond
tip bur? Or if any of you had some techniques or approaches you could
share, that would be great.

Before you guys suggest using actual gravers or hammer hand pieces,
let me cut you off at the pass by sayng I can only afford to work
with what I have at the moment which is a Foredom S and a #30
handpiece.

Thanks in advance.
Mike