For those who perform rituals, do you give offerings? If so, what kind?
What is the meaning/purpose of offerings?
The Proto-Indo-Europeans had a concept called ghos-ti. It is the origin for our modern words of stranger, guest and host. It essentially refers to a reciprocal, or mutual relationship of giving and receiving/taking, many such relationships can be found within the universe, and in fact in some cosmologies this concept explains the very nature of the universe as a whole.
This is the reason I give offerings to the Gods and spirits. A balanced relationship can't be had by only taking. It's disrespectful to the ones you're taking from, and it's doing a disservice to yourself - you won't grow if things are always just handed to you, and you won't form a complex, deep, and lasting relationship by always taking. Imagine having a friend who always takes and never gives... you might put up with it for a while, but would it really be lasting and healthy for both individuals? It's unlikely.
Do the Gods really need our offerings? Perhaps not, but it shows them we do more than take, that we respect them, value them, and that we want to share what we can with them. The same goes for the spirits, the ancestors, and the like. Different Deities/spirits enjoy different things. Different foods, drinks, scents, colors, materials, actions, and so on. Taking the time to figure out what is part of building a relationship. We can research traditional offerings, and experiment with new ones.
So what offerings do I give? There is, of course, the standard food and drink... flour, cornmeal, barley, oats, bread, honey, wine, mead, beer, milk, cream, clarified butter, spices and herbs, cookies and cakes, parts of family meals, fruits, vegetables, nuts... well, you get the idea. Even cool water makes an appropriate offering at times. Beyond food and drink, there's flowers and other fresh plants, little crafted items, beads and charms, coins, fabrics, tools, artwork, incense, candles, and more.
Time and actions can also be offerings. Dedicating the actual process of making an item, for example. A deity of weaving might enjoy the actual act of weaving as an offering, not just the finished product. A nature deity might appreciate an offering of going out and cleaning litter. Sometimes just spending some time researching the deity, or spending time at their shrine, can be an offering - making the effort to keep them in mind, and investing time into the relationship.
One doesn't have to go broke making offerings... sometimes a cup of water, a few wildflowers, and the sincerity of the gift is all that is needed.