The first seven chapters of Leviticus lay down a whole series of procedures and guidelines for the preparation of sacrifices. The record goes through each of the types of offering and describes how they were to be performed,
- Burnt Offering
- Grain Offering
- Peace Offering
- Sin Offering
- Trespass Offering
In each case, they are detailed accounts and show some specific details of how the sacrifice was to be carried out. As an example, from Leviticus 1, there is the case of a burnt offering from flock,
Lev 1:10: "`If his offering is from the flock, from the sheep, or from the goats, for a burnt offering, he shall offer a male without blemish. 11. He shall kill it on the north side of the altar before Yahweh. Aaron's sons, the priests, shall sprinkle its blood around on the altar. 12. He shall cut it into its pieces, with its head and its fat. The priest shall lay them in order on the wood that is on the fire which is on the altar, 13. but the innards and the legs he shall wash with water. The priest shall offer the whole, and burn it on the altar. It is a burnt offering, an offering made by fire, of a sweet savor to Yahweh. WEB
As with the other types of sacrifices, it has to be without blemish, and from the best of what the giver had. Here the sheep or goat had to be killed specifically on the North side of the altar, whereas with other types of sacrifices, different procedures were given. In the case of burnt offerings from the herd, or a bird there were subtle differences that had to be made to the procedure.
Amongst all the offerings the Israelites were to perform, there was't a lot of room for choice and creativity. A specific pattern was laid down, and did't allow for people to modify that or decide their own procedure.
There is some measure of choice, in terms of what type of animal to offer, and in some cases whether to offer at all in the first place, but when the offering was made, it was to be done in the specified way.
There wasn't room to offer a grander offering, like an elephant or a tiger, nor was there a choice of how to kill or cut up the animal.
Today's mainstream media values the availability of choice, and freedom of expression. From our 21st century background, we may feel inclined to want to add our own individuality to things, but there wasn't the room for this in sacrifice directions. It's like the basic school uniform. Some children love to hate the school uniform, because it reduces everyone to one level, without the ability to show individualism.
But this is something that God required in worship of him: a loss of personal individuality, and instead an obedience in following God's individuality.