The old saying that "Rules were made to be broken" has some truth in it, even when it comes to boxing. As important as proper fundamentals are, how much good technique can serve you and how valuable it is to master the rules of the ring, there are some unorthodox moves that work for certain fighters. There are a handful of select fighters, elite athletes, who incorporate bad habits into their repertoire and they not only get away with it, but are able to actually make it work to their advantage. They might be ignoring some basic, sound principles of boxing. They may be breaking a fundamental rule, or doing something flat-out WRONG and it still works...for them.
As an example, Floyd Mayweather regularly, albeit selectively, utilizes a lead, leaping left hook - which is a no-no in almost all cases. Yet, he is able to get away with it because of his speed and ability to mask it within other movements. He also uses a shoulder roll-style defense. Other fighters have tried to mimic this technique, but none do it as effectively as Floyd. His speed, awareness and how naturally he executes it, is what sets him apart. It is a part of his inner-fabric and was woven into his defense organically, because it suits his individual ability and fighting style.
Andre Ward is another example of disobeying a basic boxing rule of thumb. He regularly picks his back foot up and ends up squaring-himself off when he delivers a right cross. This is bad because it typically takes you out of position to quickly throw again or defend. His purposeful use of this technique is so that he is throwing and then smothering his opponents return punches. Many other fighters have been caught with a punch as they are falling-in, attempting to employ this technique, or are just ineffective in working it into a next move. Andre, on the other hand, is able to get away with it because of his natural athleticism and sense of timing. Manny Pacquiao does the same thing, but he is able to pull it off because of his aggressive style, his unorthodox punch variety and high volume output.
Then, there’s the oldest rule in the book of keeping your hands up. Similarly, although more blatantly than Muhammad Ali, Sergio Martinez regularly drops his hands and avoids incoming punches by slipping and ducking. He ignores the fundamental rule of keeping your hands up, but is able to do it effectively because he has fantastic reflexes and coordination. Like Ali, Sergio relies on his ability to see the punches coming, avoids them or takes the shot in stride. For all the good he's brought to the sport, Muhammad Ali ruined a legion of young fighters who thought they too could fight with their hands low, only to wake up on the canvas to the sound of "....8...9...10!"
That being said, the point is really to be careful when emulating or idolizing specific fighters and their unique styles. Some departure from the basics and what works can only be accomplished by certain individuals. Some fighting attributes are unique to their personalities and strengths. What worked for them, may not work for you because you are not them. You were born an original. There is only one you. So while it's great to learn, take characteristics and mimic fighting styles, there may be attributes you can't and shouldn't try to replicate, even if it makes that particular fighter look successful or is effective for them.
The basics may be boring, but they work. The best fighters excel from doing the basics better than anyone else, not by blatantly disregarding traditional technique. Take Sugar Ray Robinson, arguably the greatest fighter of all time, as an example. He had great hand speed, kept his hands high (for that time period anyway), utilized a tremendous jab to set up combinations and possessed knockout power in both hands. What did he do that was out of the ordinary? He performed the boxing basics to their ABSOLUTE PERFECTION. Now, that’s a good example to follow. Executing the basics of boxing, to the best of your ability, will not only look different on you, but will ultimately set you apart from the pack. There was only one Muhammad Ali. There is only one Floyd Mayweather. There is only one you. Do what you do best and if a stylistic departure from the basics comes, it will evolve naturally, not because you tried to do what so many others have already done.
Focus on developing substance more than creating style. Do what's right before what looks good and your signature move will materialize on its’ own. There are worse things than winning a world title from doing all of the basics exceptionally well. Being correct is sometimes better than being different.