Gratitude for results and help is always my preferred offering to any spirit because offering up something physical never made sense to me, as they aren’t physical so they don’t obtain what was offered. I thought about the use of gratitude in interaction with other people, and I would feel helping someone would be a waste in most cases if they did not feel or express gratitude. That got me thinking about why it is like that, and I believe it may be because gratitude is essentially recognition of power, recognizing that someone has helped you and they have the power to.
Perhaps physical offerings are the same in a way that they also recognize that this person or spirit has helped you and they have the power to, and as a way to physically show gratitude and in human relations so that the person who helped also gains something that helps their physical body to survive (in the early days usually livestock, portions of what was gained in a hunt or harvested food were given as payment)
Maybe those who speak with spirits regularly have more insights on this? I know in some cases like with Goetia spirits they enjoy the experience of the physical as offerings, so things like the taste of food, scents etc. can be given as an effective offering.
Physical offerings are given because spirits can take energy from it. Physical things have energetic copies of themselves the spirits interact with. Like if someone offers food, the spirit takes energy from it and sometimes even the food physically tastes a little “blah” afterwards lol.
An offering I’ve frequently used is a cigarette, tobacco is a very spiritual plant and (pardon the pun!) has roots in my cultures.
I’ve actually seen an entity smoke it after placing it near by. So if you want something physical and is easy clean up that’s what I’ve had success with.
I like to do a combination of both, gratitude and physical offerings. I listen to the differents enn daily as well, at least once or twice a day, to show my dedication isn’t limited to the time of the ritual.
About physical offerings like food or drinks, how often do you change them ?
Well, there’s currently a glass of rum sitting on my altar for King Beleth but I’m wondering what I’m gonna do with it once I remove it. Like, it’s good rum so I don’t really wanna throw it away but I don’t want to appear disrespectful if I drink it you know
Maybe next time you should offer up the experience instead, or along with offering the rest up. I know it’s standard in some traditions to partake in the offering yourself, and can work with the Goetia spirits.
I always drink some of the alcohol before I offer it up to a norse deity, because that’s more common in a Blót as far as I’ve read (works well either way).
I’m going to answer this seriously now and speak what I believe to be the truth. Spirits are of the acausal realm. As the OP stated, they don’t obtain energy from offerings of food etc. What provides energy to us as human beings in the causal realm does not provide them with energy in the same way, see: physics. These kinds of offerings would be symbolic, at best. From my direct experience working with the acausal, what they seek is that unexplainable quality that is shared by all sentient beings, the energy of life. Exactly the quality that separates us from the objects being mentioned here as offerings. As human beings we can ourselves become a living nexus, a portal between the causal and acausal realms. I have my own methods within my system for making offerings of this nature but I can suggest that an invocation with the mindset of gratitude and thanks may be appropriate in your own system.
I could write a lot more but you can find it for yourself, if interested, by reading, for example, Explaining The Acausal.
Having said that, you really need to experience the acausal to possess any authentic knowing.
Most entities don’t really need energy from the offerings that people give them, I sometimes doubt they even care about the offering, but rather they care about the gratitude and bond formed. Being pestered by a human who just wants you to help them get their rocks off over and over or someone who takes the time to thank them, appreciate their work, these beings are the same as humans, no one wants to keep dealing with a clingy deadbeat begging with no thank you in sight.
I think this somewhat depends on the spirits you’re working with. With demons especially, giving them the opportunity to express their power in the world is already quite pleasing to them. I have noticed a few different preferences with different types of demons though.
The goetia, for instance, seem to really enjoy partaking of physical experiences. If you perform even a very minimal evocation, and then consume some food or drink as an offering, you’ll likely find the experience to be much more intense than normal. Just eating an apple becomes an all-consuming, ferocious experience.
Lucifer and the demons in his legion, on the other hand, are generally pleased with just your gratitude. I have, however, received a few requests from Lucifer to perform some specific rituals that were for his benefit. I was skeptical at first about these requests, but they have always ended up working out well for the both of us, not just Lucifer.
plus they always aporeciate it on the emotional level.
but I don’t want to appear disrespectful if I drink it you know 
