All the different systems like the "seasonal" one (are you an Autumn or a Spring); the "archetypes", the old "Color Me Beautiful" system, etc. are fun, and are based on some pretty good principles. Of course, it isn't an exact science, but wow, there are some great takeaways in all of them, I think.
Carol Tuttle's "Dressing your Truth" is one of the most interesting to me. She identifies four different types of energy, in the way that humans express themselves. Two of them, type 1 and type 3, are essentially extraverted, "moving outward" kinds of energy, and two of them are introverted, type 2 and type 4, with movement that goes more inward. Each type manifests in how we present ourselves in the world, and the differences are STRIKING.
It's so much fun to see women discover their particular energy type, and translate it into the optimum look for them, as in this Type 4:

I've fingered myself as Type 2, the "soft and subtle" type. Sounds dull! But it fits me best, and when I dress that way I feel most "authentic"...
Anyway, enough blather. If even the tiniest bit interested, watch this video in which Carol present herself in her dynamic Type 3 persona, then tries to dress like the other 3 types, entertainingly unsuccessfully, to show that there really are identifiable principles governing the style, makeup and hair of each type.
https://www.youtube.com/watch?v=Imp-9xXfFrI
Warning-- her videos are addicting...
There's even one where she has four other style experts dressing as each other's type, with hilarious results. I'll post when I can find it again.