Love is often one of the trickiest subjects for humans - so can philosophy help guide our love lives? Well, love is a deeply personal topic, so an answer that works for one person may not work for another. But Plato has some interesting thoughts on the matter; in The Symposium, he presents three different views of love, by using three different characters as sockpuppets. Aristophanes represents the poet's approach, Alcibiades the passionate approach, and Socrates his own. I have also included Kant's approach.

• Aristophanes: In this view, each human is only half of a whole, with males being one half and females the other. Love is part of an instictual desire to feel whole, and so we search for our "other halves." While it's a romantic view, it's also problematic in a few ways. First, it's not inclusive and indeed rather condescending towards inidividuals who are homosexual, asexual, or polyamorous. Second, it leads to viewing your partner not as an individual in their own right, but as an extension of yourself - which can easily lead to abusive relationships. Third, it implies that love is "complete" once you're in a relationship with someone, when in reality relationships take a lot of work to maintain and can change over time. Fourth, it can lead to greater heartbreak if you break up, since you imagine losing part of yourself. And finally, the "instictual" argument (which appealed to gods) is dubious in the face of modern evolutionary theory, which gives a much better explanation for why humans do this whole "love" thing.
• Socrates (aka Plato's Sockpuppet): In Plato's view, our love of individuals is really part of a quest to find the Form of Beauty (harkening back to Plato's Theory of Forms), in some sort of eternal manner. Our love of individuals is just an expression of this desire, either to create physical artifact that persists beyond your lifespan (i.e. a child) or an everlasting spiritual bond (because Plato believed in that sort of thing). There are then higher forms of love, like love of honor and knowledge. This is nice and all, I guess, if you're willing to accept the existence of everlasting spirtual bonds and the Forms... but I'm not. And this view doesn't offer much in the way of practical advice.
• Alcibiades: Plato uses Alcibiades to critique love as an expression of passion; while it can be thrilling to love in such a manner, it can also lead to a lot of heartbreak. To use a common metaphor, it's like a rollercoaster; and although rollercoasters are fun and all, you probably don't want to be in one your entire life. This suggests that it may be wise to take a longer-term approach to love than Alciabdes does.
• Kant: Immanuel Kant believes you should base your love on virtuousness (according to his deontological morality), not how they make you feel. I find this rather silly. I may find someone to be a very virtuous person, but a poor fit for my personality or lifestyle, and they might feel the same about me. Kant argues that we should still go for a relationship. Why do this, if we know we would be miserable?

In case it wasn't clear, I find all of these viewpoints to be flawed in some way. After reflecting on Plato's arguments, I've come to my own conclusion that incorporates some of his ideas. Like Socrates (in The Symposium, that is, not the historical Socrates), I think it's best to view love as a mutually-agreed-upon relationship between individuals; viewing it as "completing yourself" is greedy, and it's a great way to create an abusive relationship. Unlike that view, however, I don't think love for individuals is part of some grand philosophical quest for the Form of Beauty, nor a Kantian search for virtue; rather, I'll take a more practical approach. Ideally, a relationship would bring some mutual benefit to all involved, usually emotional, but perhaps in other areas as well. In this respect, love is really no different from anything else.