I had an interesting comment posted on one of my vids the other day, basically the guy said he was finding chord changes hard when doing "proper" chord fingering, for example a 3 fingered A in the open position, whereas I was barring an A with my first finger. He wondered if doing that sort of thing would form bad habits.
Well, I can add to that - I find myself thumbing baselines on the 6th string, sometimes putting a pinky down on the soundboard as an anchor, I even have been known to sit with the guitar on my *right* leg!
But seriously, I did have classical lessons early on and technique was really rammed down my throat. Maybe it was the late 70's/early 80's, but for years technique seemed very important. Wrist position, thumb on the middle back of the neck, etc.
Over time, when I stopped having any lessons, I got sloppy with my technique, like plonking the guitar on your right leg (you just don't look cool playing guitar in the classical position - teenager era). However some things were taboo, for instance, I would never consider putting out a pinky anchor!
In the more recent years, after seeing some amazing guitarists using "dreadful" techniques, I was forced to re-evaluate my stance. Now it is a case of "if it makes it easy for you, and it is comfortable, then do it."
Lets look at "easy":
* it should be easy to perform quickly and accurately;
* there should be no short term/long term discomfort or pain in performing the technique.
Generally, since mankind has been playing guitar-like instruments for hundreds of years, the established techniques taught should be best. Let's face it though, firstly, what is "generally" the best technique might not be the best for you. Secondly, innovation is what drives development. Would Jimi Hendrix have come up with such stuff if he was playing the guitar the right way up? Would Elizabeth Cotton have created "Freight Train" if the guitar wasn't strung upside-down - i.e. playing the bassline with her fingers and the treble with her thumb?
Okay, they are extreme cases, but the point is there: Typically, perform the generally accepted techniques, but if you are getting better results with "bad habits" and it's not hurting you, then why not.