Good posture for guitar:- is it cool?

Hi to all lovers of music and guitar playing in particular. Have you thought about how your posture and position of wrist, arm elbow affects your ability to play? These are things we are often not conscious about but when an experienced teacher takes a look, it can be really obvious that one or a combination of these things can be hampering your ability to hold down certain chords or your ability to articulate certain runs and riffs.

Another important thing is the length of your guitar strap! It may look cool to have your guitar strung down close to your knees but the sacrifice for fashion is severely restricted ability to play...OK if you are only playing some basic stuff, fair enough maybe the fashion statement becomes more important...but if you are developing your playing it is good to get out of certain habits!