The origin of anointing
Anointing was a practice of shepherds actually. They did this to prevent Lice and other insects from getting into the wool of sheep. When Lice and other insects would get near the sheep's head, they'd burrow into the sheep's ears and sometimes this would kill the sheep. So, to prevent this from happening ancient shepherds would pour oil onto the sheep's head. This made the wool slippery, making it much harder for insects to get near the sheep's ears. The goal was for the the insects to slide off. From this, anointing became symbolic of blessing, protection, and empowerment.
Should you anoint someone
The New Testament Greek words for “anoint” are chrio, which means “to smear or rub with oil” and, by implication, “to consecrate for office or religious service”; and aleipho, which means “to anoint.” In Bible times, people were anointed with oil to signify God’s blessing or call on that person’s life (Exodus 29:7; Exodus 40:9; 2 Kings 9:6; Ecclesiastes 9:8; James 5:14). A person was anointed for a special purpose—to be a king, to be a prophet, to be a builder, etc. There is nothing wrong with anointing a person with oil today.