Finally one good question instead of the typical
ones we would normally encounter in AA.
***
CloUdiSm recognised love as a separate entity from
a relationship. Love transcends all forms and BGR is merely one
dimension of how Love can manifest into. Ironically, the existence
of a relationship might not be, though it should have been, a
relationship based on unadulterated, altruistic model of love. The
higher octave of Venus lies Neptune and that's where the divine
power of love perched itself beyond all marked boundaries,
incarcerated by previous self doubts, fear and all elements of
negative forces and would transform itself into one hell of a
formidable force. But the sad truth is that most couples hardly
reach there - often slaughtered by realities of life like a doomed
infantry amid heavy crossfire.
I wouldn't say finding a good partner is much more important than
finding a good formula and equip yourself with the right wisdom to
ensure a fulfilling relationship. Everybody have different
successful love formulas, but what works for people may not
absolutely mean it's the same for you. People always talk about
jerks seeming 'winning' the game of love, but I can tell you Mr
Nice Guy can also win being Mr Nice Guy - it's only a matter of
strategy. I can tell you the factors influencing
our fate and destiny in love, in which you could form your own
secret equation based on your personal life and make the best out
of things.
As a general rule, the reason why others love secret to success
may not always be 100% applicable:
i) We all have different but stated amount of cosmic lessons to
overcome this lifetime.
ii) We have different and various degrees of karmic bonds with
different people, which will trigger off our cosmic lessons in life
and reverberate different results based on our freewill (Law of
Cause and Effect).
The four elements, also known as Quadruplicity, are the basic unit
of life and quoted in CloUdiSm (Elements Of Relationship), it is
also the four factors that pervade every love relationship - Fire,
Air, Earth and Water. In qualities it refers to Willingness,
Communication, Trust and Understanding, but as factors of a
relationship:
Fire rules Lifestyles.
Water rules Heartware.
Air rules Communication
Earth rules Material Possession.
Every love is subjected and affected by the theory of
Quadruplicity. Theoretically speaking, a lack/concentration of
either element would upset the overall balance and harmony of the
relationship. But realistically speaking, most relationships have
uneven mix of these thingy.
From the effect of Quadruplicity, it will generate two phenomenons
- Complementary/Similar effect, but generally a mixture. Similar
effect refers to two people with similar qualities/conditions in
themselves that spark off reasons of attraction. It promotes
harmony, but sameness.
E.g. We both have a liking for sports, sun and the sea.
Complementary effect refers to qualities/conditions in themselves
that complements one another that spark off reasons of retention.
It promotes conflicts, but higher awareness.
E.g. I am a blur queen and he's more streetwise. But at the same
time, I am thrifty while he's a spender.
Going back to answering your question of 'How do we know who is
right for us as a partner' - seek for the one with enough
similarity to forge attraction, yet not too much to limit mutual
exploration and one with enough complementary qualities to
compensate, yet not too much to create overwhelming
conflicts.
You must go through your baptism of fire to learn about the
'correct equation' needed for you to have a decent, fulfilling
relationship. There's only so much you can learn from others and
nobody, other than yourself, can give you the best strategy in your
game of love.
P.S: Our life calculates the introduction of karmic or benefic
bonds based on previous incarnation and current planetary
movements. Most of the time, we can't actually prevent the
manifestation of our cosmic lessons, but what we can do is to
outsmart our cosmic lesson by having the wisdom to learn FASTER
than the time it takes for our cosmic lesson to teach.
In school, the most intelligent fellow will probably perform the
best. In love, the accolade goes to the one with the highest
wisdom. 
Cheers