Using perfume and cologne in a spiritual and magical context might seem deceptively simple -- you put it on your body and let it do its work, right? While this is certainly a valid use, there are a great many other ways to tap into the power of these scents. When looking at colognes and perfumes, try to avoid seeing them as just fragrances. At their heart, they are herbs, resins, and oils in an alcohol base. This may give you an idea of the abundance of magical uses of colognes and perfumes.
Before You Begin
It is not enough to buy a spiritual perfume and begin using it. To get the most benefit from them, they need to be consecrated. This means that you need to declare what the purpose of the perfume is. This can be something very simple, like, "I dedicate this perfume to drawing prosperity into my life." You also need to meditate or pray over the perfume, visualizing it working for its intended purpose. If you choose, you can ask your angels, saints, and deities for help to make it more effective at whatever you want it to do. If you prefer, you can even set up an entire ritual around the consecration, including lighting appropriately colored candles, petitioning higher powers, lighting appropriate incense, and making offerings for their aid. After the perfume or cologne is suitably consecrated, it can be used.
Perfumes as Offerings
Many deities enjoy perfume, especially those associated with love and beauty. Other deities like receiving perfumes that contain their favored ingredients, or that are crafted specifically for them. Aphrodite, the Greek goddess of love, enjoys offerings of gardenia and placing Gardenia perfume on her altar would be appropriate. (And in rituals where "outsider" spirits are given offerings, leaving some perfume just outside of the ritual space can help keep them from bothering you!)
Scents in Your Space
Perfumes and colognes are placed on the body to give their properties to the wearer and, by extension, can do the same to a place or building. As alcohol-based infusions of herbs and mixtures of oils, perfumes and colognes can be added to washes or sprinkled around the boundary of a place. A love perfume would be a good choice for a bedroom, around a bed, or other romantic nook. If you are seeking to defend yourself from misfortune, enemies, or other bad things sent your way, then Protection or Saint Michael perfume can be used to help fortify your home's magical defenses and protect those within it. If you have a place of business that could use a boost, then Success perfume might be a good choice for adding to a floor wash, or sprinkling around the perimeter, by the front door, or around the cash registers.
Using Scents in Ritual
Sometimes, adding perfume to rituals might be a good idea. If you perform a healing ritual that involves drawing a bath, for example, you may choose to add Saint Lazarus perfume to the water while praying for healing. Other times, it might be a good idea to spray someone with perfume in the middle of a ritual. This can function as a symbolic gesture, where the perfume represents the blessings being rained down upon someone, as well as adding the power of the perfume to the spell itself. Rituals for love, success, or prosperity are a good choice for this.
Perfumes as Spiritual Food
Just as perfumes can be given as offerings to spirits, they can also be offered to sachets, witch bottles, mojo hands, guardian dolls, lodestones, crystals, and other tools or vessels. The best way to do this depends on the tool and material in question -- lodestones and crystals can be washed in perfume, and witch bottles can have some perfume added to them, but fabric items like sachets or dolls should be fed by dabbing a bit of the fragrance on them instead.
Never underestimate the power of scent. The magical uses for colognes and perfumes extend far beyond simply wearing them. If a liquid is called for in a ritual, often a cologne or perfume can be used or added to it to endow the liquid with its properties. Otherwise, let your intuition and your spirit guides lead you to the perfect scent to complement your spiritual journey.