LOVE IS THE MOST POWERFUL FORCE IN THE UNIVERSE.
IMPORTANT - It’s important to not write the name or use a picture of anyone who doesn’t consent or know about magick in process. We want to avoid any karmic debts or messing with other people’s free will. If both/all parties are consenting, then it’s fine. Eg marriage difficulties where both people agree that they wish to heal and obtain the best possible outcome.
Love spells directed at someone without their consent is manipulative. Some would argue that is what magick is - manipulating energy - however you're treading on shaky ground if you are coercing an outcome via magickal means that the person wouldn't normally do.
We also need to consider consequences of magick. If you are wanting "Sam" to fall in love with you, and you perform a spell with this exact intention in mind, and Sam turns out to be abusive, or just not the right fit for you - then you could end up with more drama and troubles than you intended on. Maybe the Universe has someone better in mind for you?!
The most foolproof method is for you to focus your intent on having the most loving and healthy relationship. That allows the universe to align you with the highest and best possible outcome, rather than targeting ONE person, you are leaving it open for interpretation.
If you are focussed on one person - because let's face it, sometimes it needs to be done, you could use the same method as above and word it like "Sam and I have the healthiest and fulfilling relationship possible".
You never want to start a relationship as a prisoner.
You can replicate sex, lust and obsession, but you can't replicate love.