Yes and no.
If the spell is meant to manipulate another person, then no, it is not ethical. Manipulative love spells can prove to be harmful, and often do.
I know I have posted some love spells here that meet the 'manipulative' description, but also take note that with every spell of this type, I also post a warning stating the risks of using it. Let's face it- there are so many manipulative spells and hexes out there already, and if you want to cast such a spell, you're going to find a way to do it, whether I provide you with the spell or not. Sometimes we feel we need to ignore ethics and do what is 'needed', and in doing so, we're casting at our own risk. Just don't say I didn't warn you.
Now, if the spell is meant to help you find the right person, or to make you more attractive to others, that is okay, as long as you are not out to harm another, or even yourself for that matter. There is nothing wrong with a good confidence booster, if that's all it is, and you can find many spells like that here.
Remember: harm none.