Offerings
Every time you ask "How do you give offerings?" you will get a different answer. Every tradition and practitioner has their one way. You might start out one way and, as you progress and get more comfortable, discover a better way for you.
Here's a simple, general example:
Routine
If you struggle at all with getting distracted, forgetting, or keeping focused, it's a good idea to create a routine for when you plan to give offerings. Things might come up outside of the routine too, but this way you have certain times you know you'll give offerings.
This could be once a week, part of your morning and/or night routine, even once a month. This is entirely up to you, the deity, and what you feel comfortable doing.
As an example, I give offerings for Aphrodite on Fridays. I offer to her on other days too, these are usually spontaneous, but I know Friday is the day I will always give offerings.
Offering Spaces
If you have the means, an offering dish and a candle are good things to include in an altar or offering space. A representation of the deity or spirit might also be a nice addition. These are not necessary, though.
You can create an offering space or temporary altar by just setting a regular cup there with the offering inside. You can, it the case of food or drink offerings, offer to a deity or spirit by consuming the item yourself and letting them know that it is for them. Though, this should be discussed with the deity or spirit beforehand.
What should you say?
You don't need to say anything. You can just hold the spirit's name in your head as you set the offering out. If you choose to say something, it can be anything that makes it known that the offering is for the deity or spirit you intend. Here are some common examples:
~ "[Spirit name] this offering is for you."
~ "This [insert offering] is for you, [spirit name]."
~ "I give this offering to [spirit name]."
~ "I present this offering of [offering] to you, [spirit name]."
~ "Here you go [spirit name]."
~ "[sprite name] this reminded me of you."
If you are offering food or drink through yourself and choose to say something, here are some examples:
~ "I offer this [insert offering] to you [spirit name] through my consumption of it."
~ "This is for [spirit name]."
~ "I invite [spirit name] to enjoy [offering] through me."
Disposal Of Offerings
If the offering is environmentally friendly, you can dispose of it by tossing it outside to return into the Earth.
If it isn't environmentally friendly, it's best to be safe and toss it out in the trash bin. Explain that you aren't aware of a safer way to dispose of it, or discuss it beforehand with the deity or spirit, if you're worried at all of offending them. Though, it wouldn't likely offend them, they are aware of the situation.
If it's a physical object of some sort, you can leave to in the area if possible. If not possible, you can put it up somewhere safe. Maybe keep offerings like this together in a safe place.
Note
Offerings do not have to be food or drink. They can be crystals, flowers, art, reading of something, or any other object.
Offerings do not have to specifically be associated with the spirit in question. This is one way we get UPG.
If anyone who might be reading this is comfortable sharing the way you give offerings, please do so!!