Isabel Toldeo, Mistress of Style, drawn by Ruben Toldeo. (See her work).
Notable style is a difficult characteristic to achieve because it is a personal statement that is consistent and people have issues with all of those -- stating something publicly, revealing something personal and being consistent. It is hard to do and requires discipline, knowing yourself well and also an easy facility with the art principles. Lots of people simply say "too much trouble" and go the identity clothing route, a uniform and a cop-out.
Because of the complexity of living with style, many make it as simple as possible or they copy a celeb or they shop a single store -- in other words, they adopt a style. That's easier than inventing one but usually results in over dependence on brands and requires serious money. The prevalence of this approach now accounts for design houses turning into nothing but brand management offices. However, there is "another way to go'.
In the other approach, style comes from authenticity, meaning that you spend your money (top down) on a great haircut/color, makeup, good foundation garments -- the fundamentals, so that most anything you put on will look attractive. You keep a consistent regimen for these basics and eventually you will have tweaked them to express your own uniqueness. Remember, attractive all the time is better than stunning once in awhile.
Next, the clothes. Again, aim for basic authenticity -- best colors, good fit, workmanship and fabrics. Make time to learn what constitutes 'good' in these four areas -- it's a one-time learning curve. And think, you are going for style, not fashion, so ignore what is hot (no matter the discount) unless it fits your style. Think of knowingly buying the wrong thing as a form of self-betrayal -- not good.
And now for the art principles. The two big features are structure (the cut/fit of the garment) and decoration (the surface features) and they always have a non-verbal message, communicated visually. I know all the social heat a and light is generated by surface features but the real you is in the cut of your clothes. Ask yourself what message is being sent to viewers by your choices. Over 50% of communication is non-verbal so what they see becomes what you are (to them). This is even true internally -- human beings actually begin to act the way their clothes look. So these are important, conscious choices that will have an affect on your life in many ways.
And now for one last thing and a starting point for young people. Style maturation happens in a prescribed way. When in high school, people tend to focus on the wattage of a single piece, as in "if only I had a ______", then I would be cool. The mental biology hasn't advanced enough to take in the whole person as a single visual identity. Later, one learns that it is 'the look' that counts, the whole look. Seeking compatible pieces, orchestrating their balance, staying on message is a personal growth thing, eventually leading to an integrated wardrobe that expresses your personality.
It is then that you are authentically you -- and, BTW, amazing. Amazing is always the result since another human characteristic is that people will ascribe qualities to you personally that are expressed by your appearance. You can be thought of as smarter, richer, younger, etc. -- by manipulating your 'message' to the desired effect, for example, you can advance your career. But don't go overboard with this or you forget who you are and wind up back at paragraph one.
To begin the learning curve, there is a great site for college age people that puts together whole looks. Some are more expert than others but they do a great job with the 'message', making sure it is identified, complete (always hosiery), consistent, current, functional and appropriate for the age level and student life. Their choices can be modified for older people (men & women), working people and those who have already found a mate but the core themes and the rationale for their selections are excellent. See College Fashion.
A person with a disciplined style is perceived to be more interesting, trustworthy, friendly and confident so make people feel good, dress with great style!