Dear Reader,
Offerings are a big deal. They are part of the glue that keeps the relationship between you and the spiritual beings in your life chugging along. There's a lot of competition between folks who post pics of their altars as to who is giving the best offerings and such. There is also a great deal of unverified personal gnosis that is flying around the community as to who likes what offerings and dislikes what other offerings. Don't let all of this talk discourage you.
While offerings are a big deal, they don't have to be expensive, brand name, or luxurious. They can be simple, humble, and as mundane as a shiny stone you saw that reminded you of Them. One of the most common offerings when one is on a tight budget is water. Some may scoff at water being an appropriate offering. For millennia, potable water just couldn't be had. This is why so many ancient cultures brewed up things like beer, mead, and wine. Yes, there was alcohol but the alcohol in it was what made the water safe to drink.
Your Mesopotamian spirit friend may be quite bored with beer, as it was their everyday beverage. Giving a glass of clean water would be a delightful change of pace for them. Offering common modern beverages is also an option. Popular rumor has it that Loki enjoys an occasional bit of Mountain Dew. It doesn't have to be a special wine glass or something you inherited from your great grandmother's china to serve it in. It can be in a mini-plastic cup (they're basically shot glasses but don't call 'em that).
Breads of many forms are staples of offerings. This doesn't have to be the case. You can put out some cookies, bake some biscuits, or make an extra serving of oatmeal in the morning. Indeed, you can put a small portion of your meal aside for Them. Don't go too far and sacrifice your health in order to express you affection and devotion. Your spiritual companions want to see you doing well and as healthy as you can be. This leads to a third option in giving food or drink. Dedicate your first bite/sip to your spiritual companions. For people who come from a Christian background, this may be a bit awkward at first.
If you have been raised in a custom where you ask the Divine to bless your meal, you can compose a blessing dedicating the meal to your spiritual companions to be said (whispered or thought) over the meal before you eat.