I've made reservations for myself that I ended up giving to other people. All I did was call the hotel, add the person's name to the reservation, and let the front desk know that I would be paying for the reservation. The few times I've done it recently they've sent me a credit card authorization form so I could verify that yes I really wanted to pay for the reservation for this other person. All above board. No questions. All the other person had to do was go get their key from the front desk when they arrived.