Love spells. They're one of the things that often draws new folks to Wicca and Pagan religions. However, there's a lot of question within the Pagan community about the ethics of casting a love spell on someone else. After all, if you're performing magic on someone without their knowledge, aren't you messing with their free will?
Most Wiccans will tell you that the best way to approach love magic is to avoid focusing on a specific individual as a target. Instead, use your energy and skills to focus on yourself -- to draw love your way, or to help you present yourself as a person worthy of love. You could use your magical abilities to feel more confident and attractive, much like a magical makeover. In other words, fix yourself, not someone else.
Bear in mind that many Pagan traditions have no restrictions on the use of magic to change someone else. If you're part of such a tradition, the use of love magic may well be within the boundaries of your ethical guidelines. In some traditions of folk magic, love magic is perfectly acceptable. It's something that's done as a matter of course, and is no more unethical than wearing a sexy perfume or a cute push-up bra. Magic is viewed as a tool, and can be used in tandem with the mundane to bring you what you want -- after all, if you didn’t want to change things, you wouldn't be doing magic in the first place, right?
Before casting any sort of working that affects another person, though, be sure to think about consequences. How will your actions affect not only you, but other people? Will it ultimately cause harm? Will it cause someone to be hurt, either directly or indirectly? These are all things that should be evaluated before performing any working at all, whether it's a love spell or some other type of magic. If your tradition or belief system prohibits you from performing magic on someone without their consent or knowledge, then you'd be better of skipping the love magic, and focusing instead on self-improvement and self-empowerment.
Rather than aiming a love spell at someone and expecting them to become your devoted servant and doormat, consider looking at love spells as a method of (a) getting someone to notice you AND (b) getting the person to, once they've noticed you, find all the things about you that they like. If you maintain this perspective, you should be able to work love magic and still keep within your ethical boundaries.