Hard to find any recommendations for things to see or do on the Greek island of Milos, a place commonly described as "looking like the moon"...
Even jumping on popular tour aggregators may simply result in 10 or more variations of the same beach or sailing tours.
There are a few local sites to consider, however, in addition to the plethora of beaches. Greece's only Christian catacombs, for example, lie to on the western slopes of Trypiti.
I'm not entirely sure how much time to dedicate to this site, maybe travel time to cover the 1.5km or so from the port area in Yankos and I've read about 15 minutes of guided tour time. Might see for myself in a few short weeks!
Closer to the port areas are obviously tons of options for dining & drinks, there's apparently a winery on the island. But the area's historic obsidian trade may provide an excellent opportunity to see some killer rocks. No pun intended.