Oranges and lemons are pretty wonderful in that they are both interesting components in a number of love spells.
Lemons are used in both love and separation spells, as well as cleansing. The oils and leaves of a lemon plant can be used in ritual baths. They can also be used as a way to “cleanse” your life of something, hence the separation aspect. Lemon zest, rinds, juice, and peels can be used in baking something with a love intent. Best to use sugar with the lemons for better effect.
Oranges, on the other hand, don’t have the cleansing/separation aspect that lemons do. Instead, oranges have become a symbol of the Sun and solar energies. You can use orange peels in tea, potpourri, charms, sachets, etc. Orange helps light the way, aiding the lost and confused. It is a pretty nice addition to Yule ceremonies and rituals. Orange parts can be used for the worship of certain God/desses and in a number of spells involving love, finding purpose/direction, or to offer to a God/dess during ritual.