Museums and Food are in the third tweet.
Macau is a favorite one-day trip. Could do 2 days. The outlying islands are interesting as are Walled Villages, archeological/cultural visits in NT/SaiKung, and of course, dim sum.
The HK Museum of History, HK M of Art, HK Heritage Museum, Sheung Yiu Folk Museum, and Flagstaff House Museum of Teaware (kind of cool, if niche) plus the tiny places at historical/cultural sites are all worthwhile.