祝い and 贈り物: congratulations and a gift
Distinguish celebration from a physical gift, tracking sender, recipient, and preparation.
Expressing congratulations
祝い, read いわい, means celebration or congratulations. 合格のお祝いをしました。 means celebrating someone's passing an examination.
お祝いの言葉を伝えました。 means conveying congratulations. It does not necessarily involve handing over an object.
The gift itself
贈り物, read おくりもの, means gift. 友人への贈り物を選びました。 means choosing a gift for a friend.
友人から贈り物をもらいました。 means receiving a gift from a friend. Distinguish the recipient with への from the source with から.
Purpose and delivery stage
お祝いとして花を贈りました。 means sending flowers as congratulations. Celebration is the purpose; the flowers are the item sent.
贈り物は用意しましたが、まだ渡していません。 says that the gift was prepared but has not yet been handed over. Preparation is not completed delivery.
In 友人への贈り物, is the friend the sender?
Show the answer and why
The friend is the intended recipient. A gift from a friend can be expressed as 友人からの贈り物.