Although I really hate Bardon's sanctimonious, didactic style of writing, the soul mirror exercise in "Initiation into Hermetics" (Step I, Magic Psychic Training) is well worth doing despite all that. It's a sort of personality test, a psychological assessment of oneself, and I must say the result really surprised me… it explained why I reacted like I did in crucial situations of my life, why I made certain mistakes or choices or why I always feel drawn to this or that extreme.
I'm not a huge fan of the idea of equilibrium or balance. Movement, after all, is the result of imbalance - I read somewhere that simple walking was just a controlled way of falling forward. Equilibrium, on the other hand, suggests something static to me that is vulnerable to the slightest impact of any external force. I just realized that this bold pronoucement may be the result of my elemental makeup, too.
Bardon's soul mirror showed me which elements (and thus qualities, types of behaviour or strategies, etc.) I lack, and boy, it was spot on. For me, it's not so much about balance, it's more about "I want some of that!", crudely put. You don't even have to do the soul mirror exercise, just look deep inside yourself and see what virtues, qualities, characterics, etc. you wish you possessed. Then see if you can attribute them to one or two (not more!) elements. As the four elements correspond to the four LBRP archangels, you are now presented with a living embodiment of that element and can begin working with it - by "working with it" I don't mean a formal invocation or evocation, just thinking about your (underrepresented) archangel, getting to know it, meditating on it, maybe write a little prayer or poem for it (I call it 'the romancing method'

), and that's what I'm currently trying to do with one of them.
Example: You have courage but often rush in recklessly and take unnecessary risks, so a little more circumspection and healthy caution (earth) wouldn't come amiss. So you begin contemplating Uriel/Auriel - or reflect upon earth in general, how it's firm, reliable, not easily moved, etc., in one word: boooriiing!

. It can be a real eye-opener and even fun. A strong foundation for me means knowing myself thoroughly, warts and all, eliminating all my weakness and flaws would just take too long, I'd never get anything done if I patiently waited to attain that precious elemental equilibrium (which attituce is probably also indicative of a certain elemental imbalance

).