Hilchos Maasei Hakarbanos 3:13

The one laying hands must do so with all his strength, with both hands on the animal’s head, as per Leviticus 1:4: “on the head of the burnt offering.” We see that his hands must be on the animal’s head and not on its neck or on the sides of its face. We also see that there must not be any interposition between the person’s hands and the animal.

Hilchos Maasei Hakarbanos 3:14

The laying of hands was performed as follows: for offerings of the greatest sanctity, one would stand the animal in the northern section of the courtyard, facing west. The one laying hands stood to the east, also facing west. He would place both hands between the animal’s horns and recite the confession for the sin that caused him to bring the sin offering or the guilt offering, as appropriate. For a burnt offering, one confessed for negating the observance of a Torah obligation or of a Torah prohibition that could be corrected by performing some action.