Advice Please - Portraits!

Hi guys,

I'm not a portrait model.  I try to avoid looking at the camera because I'm afraid I'll crack the lens!!!

If ever there is a photograph you can guarantee I'll be unhappy with my face in it.  Oh the joy of being able to wear a mask!

Okay, even a ball-gag, it all helps!

But, here's the issue.  I'm in the process of becoming a Personal Trainer and I need some images to sell myself as a fitness-guru and art nude just isn't going to go down well at my local gym!  I've also signed on to some acting/extras-work sites and I need headshots.  Preferably ones without cracked lenses!!!

So, here's my question; when you need to buy glasses there are all these adverts that say certain styles flatter certain shapes of faces and that "we have a computer which can match the style to the shape of your face" etc.

Faces are asymmetrical, I'm happier with one of my profiles than I am the other (but I can never remember which one!).  I have a weak chin and I have found I can achieve a stronger look by pushing the jaw forwards a little (although I have to be careful I don't end up looking arrogant or angry!).  Portrait photographers have suggested I google images and look for expressions which work with my face, but (a) most male models I've googled only seem to have one expression and (b) I can't find one that works for me - not in a portrait sense (in art nude etc I often find that, where the subject dictates it, a snarl works well with my features but I can hardly snarl at my PT clients!).

Is it possible that certain angles, certain expressions suit certain kinds of faces?  Is it possible to be a bit scientific about this and say, "I have a round face with strong (think Bond--Villain!) eyebrows therefore It's better to be looking upwards to emphasise the jaw and stop the eyebrows from trying to steal nuclear weapons." ???

Does anybody have any modelling/posing tips?

Or should I just do my Personal Training in a mask?

Or a ball-gag...

Kind Regards
Dave