This information has been collected from my interactions with spirits as well as through conversations with other practitioners. Be aware of your local laws before bringing any of these things into your ritual landscape.
With that said, most inhalants are intoxicants that change the way you interact with your ritual and, in turn, the world around you. Be it tobacco, damiana, datura, cannabis, mullein, lotus, salvia, DMT, or some other substance, you're going to be in a different state of being. That differing state of being should be planned for and planned around if you want something useful to come of it.
For example, tobacco contains nicotine, and the plant itself is part of the Solanacea family, meaning its related to datura, eggplant, mandrake, deadly nightshade, and henbane. By extension, tobacco does have a manifest link to death, the underworld, and nightside entities of all kinds. Cthonic powers tend to harmonize well with it, and some cigarettes contain menthol, which also influences spiritual manifestations rather sharply.
Knowing this, if you choose to smoke a cigarette before you walk into a rite, be aware that these entities of the earth and lower realms are going to be closer to you as a result. That's not the time to be trying to contact angels unless you're working some pretty substantial grounding magic with them, and that's not a good idea for most novices. (Good way to burn yourself out)
Instead, plan around this and perform daemonic works, ancestor-related rituals, and connection works through beings like Scirlin, as they'll be more harmonized with your sphere of influence at that time.
Lotus, on the other hand, is an entirely different beasty, and its connections are far more celestial in attachment. Its been used in Buddhism and Khemeticism to connect with heavenly beings of all kinds, and while it is a mild hallucinogen, it tends to distance us from our feelings for a time, making it incredible for transformative works when contacting angels of healing & transcendence.
Damiana is a bit different and often called an aphrodisiac, but its deeply connected to the moon and its tides. By extension, it works well with matters of illusion and can be used to contact sublunar spirits like succubi, as well as help with appropriately lensing very strong astrological energies into your life in a meaningful, practical, and ultimately helpful way. This can be pretty rough to handle, but its nothing like salvia.
Salvia divinorum is an incredible substance, but that doesn't make it particularly friendly or comfortable to work with. Its an herb that creates strong hallucinogenic responses in the mind, and it immediately connects one with the Qliphotic spheres of existence. Because its something of a delirient, its not often an enjoyable experience, but that's also what gives the plant its ability to force us to connect with the things we choose not to observe. Its dysphoric nature creates lasting internal shifts, and it is uniquely suited to serious nightside works.
These are simply examples of the many different things one can achieve with herbs of various kinds, and there many, many more plants and materials out there that can influence your mindset and process during ritual. Consider how best to involve these in your works if they appeal to you, as whether smoked or placed on a coal, they make a distinct splash.
Tread carefully.
Blessings,
Chris