I've always said no when people asked - I have way too many bad habits
Would I be any less of a gentleman if I asked what bad habits you have?
Me, I bite my toenails, pick my nose, and scratch my . . . .
OH! You meant bad habits with glass.

I'm so embarassed . . . .
There are no* "bad" habits doing glass, just differing techniques . . . grin.
* - (there are some definite no-no's we all know. These fall under ground rules.)
I'd been doing glass for 30 years before I took my first class. The store owner
and sales staff knew my abilities, but the class instructor had no idea who I was.
The first time I cut glass in the class, she was all over me, telling how I laid my
score was totally wrong. It couldn't be done. Boy was she embarrassed when she
found out I'd been cutting glass almost as long as she'd been breathing air.
As mentioned elsewhere, in the introductory forum, our relationship went
rapidlly downhill over the next six sessions.
I've taught a couple dozen people glass work, and always showed them several
different techniques used in each stage of production, stressing, in most cases,
there is no right or wrong way, and over time they would likely develop thier
own way.
I'm not a people person, but teaching glass was one of the most rewarding experiences
I've had. There were about 4 people I couldn't cennect with, or relate to, and they
ended up taking lessons from the store owner. I had no use for them. But the
others, what a thrill watching thier faces as thier creations sprang to life, it was
priceless. Knowing the answers to thier questions before they even finished asking
them.
If you get a chance to teach, take it . . . it's almost as enjoyable as the glasswork
itself.