In this kind of relationship, personalized gifts, books, electronic products, food, and experience gifts can be given on birthdays.

1. Personalized gifts: Customize gifts according to your friend’s personality and interests, such as customized T-shirts, accessories with their names printed on them, customized portraits or engravings, etc.

2. Books: If your friend likes to read, it would be a good idea to give them a book that interests them or a book that they have always wanted.

3. Electronic products: If your friend is interested in technology, you can consider giving some electronic products, such as smart watches, headphones, game consoles, etc.

4. Food: If your friend is a gourmet, giving them some of their favorite food or special ingredients is also a good choice.

5. Experience gifts: such as movie tickets, concert tickets, travel packages, etc., giving friends the opportunity to experience new things.