What are some thoughtful and unique PhD gifts for him that would make a memorable and meaningful gesture?

Some thoughtful and unique PhD gifts for him could include a personalized leather-bound journal for his research notes, a high-quality pen set, a custom-made bookshelf to display his academic achievements, a subscription to a scholarly journal in his field, or a gift certificate for a special experience like a hot air balloon ride or a gourmet cooking class. These gifts can show your appreciation for his hard work and dedication in earning his PhD.