There are so many approaches to this and so many conditions with which to contend, that it's almost impossible to say "this is what you need to do". Check out Andrea Guarino-Slemmons setup. Check out the various studio builds on the studio page here. There's too many ways to do it, but the one most important principle is, get enough draw that it pulls the fumes/particles away from your face.
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ESC
Soft glass on a Minor/concentrator since 1996
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