So you want to make an offering but not sure where to start. First is to understand a bit about what was seen as impure. Impure things include plastic, wool, and certain animal products, for instance anything that has urea in it (this can be found in many types of perfume, soap, and cosmetic products, and is a derivative of animal urine). Some argue that silk is impure because of how the silk is formed. Others say because of how the silk is generally harvested that it is against ma'at, therefore is impure. So from what I've gathered a general rule of thumb an item that contain animal product(s) is impure if it contains animal waste or was gather in someway that would be against ma'at, with the exception of wool. Wool was seen as impure in the temples because the priests would sit in the temple pools and the wool would mold.
Menstruation is another thing that is said to be taboo but I heard that Egyptologists argue over whether is really was bad or good. So I have some looking into on that. Menstruation comes into question because bleeding while in ritual is usually looked down upon.
(Another thread will be started to discuss more in depth about purity)
Ok now that you know some of the taboos now the questions becomes "What should I offer?" Sure you could go to Google and look up Netjer X and see what people list for offering to that god/dess (Caution: If you do do this most of what you'll find is a person's UPG. I'm sure people didn't have laptops in AE to offer to Djehuty. cat_whee Yes I did actually find that on an offering list for Djehuty.) but what if you're still not sure what to offer? Egyptologists have noted a number of things that were commonly offered.
Common Drinks:
-Beer
-Wine
-Water
-Milk
Common Food:
-Bread
-Biscuits (or any baked good in general)
-Figs
-Beef
-Dates
-Grapes
-Wild Game (gazelles and oryxes are cited)
-Water fowl or duck
-Pigeons
-Honey
-Vegetation or Fruit
-Onions
-Salt
-Grains (barley, wheat, flour, etc)
Common Non-Food Items:
-Incense (this was a staple in almost every ritual)
-Natron (also a staple)
-Papyrus (sheets or the plant material)
-Wood for heating and cooking
-Flowers
-Jewelry/Riches/Gold
-Clothing or bolts of fabric/linen
-Oil based perfume or unguents
-Ib Heart
-Ma’at
-Ankh
Ok now you have what you're going to offer and have offered it. Now you're probably thinking "What do I do know?" That depends on who you were doing an offering for. And I don't mean which deity. At this point you're probably giving the screen a weird look and going "What do you mean Yami?" Up until this point I've only really mentioned giving offering to the gods. In Kemeticism there are also offerings given to ones Akhu ("Blessed Dead" or "Shining Ones" basically a person's ancestors. I'll go over Akhu more in another thread). The only difference though is in how to handle consumable items after offering them. When offering food or drink to a deity its highly recommended to consume the food and/or drink after offering it. If it was offered to one's Akhu though its considered not good for us to consume so its suggested to give it to the wildlife/plants or just throw it away. Non-food items can either be left on the shrine or stored close to it.
Source:
The Twisted Rope
And I forget where I got the purity stuff from. cat_sweatdrop