I apologize if this has been answered a million times, but I’m looking to spend about 6 or 7 nights between Santorini and one other island. It will just be for my wife and I for our 15th wedding Anniversary. This will likely be a late September or early October trip. I want something easy to get to from Santorini as well as getting to Athens. We’re not super into all the historical stuff, but still wouldn’t mind seeing some of it. Our biggest interests would be amazing food and drinks, beautiful scenery/beaches, and probably just a lot of walking around and checking out the local villages and culture. I’ve been going back and forth a ton between Naxos and Milos mostly, but have also thought a little about Sifnos too. Any advice would be much appreciated because I’m driving myself crazy trying to figure this out!
We paired Santorini and Naxos (Santorini 3; Naxos 4) and were very happy with our choice. You can fly back to Athens from Naxos. Naxos has villages, beaches, and hiking.
Milos I think is another volcanic island so maybe not the best choice with Santorini if you want a contrast.
Sifnos is known for walking so a good choice as well.
And don’t drive yourself crazy. Whatever you choose, you will enjoy.
I agree on choosing Naxos, especially since you love food. It's a big island with a lot of traditional places to eat and beautiful scenery. I think you should pass on Milos right now, as the ferry schedules aren't always reliable this time of year and the weather can be unpredictable. The Blue Star Ferry is usually a safe bet, as they tend to keep running even when it's windy.
I've never done it, but the two I've always wanted to try were Anafi and Folegandros.
Santorini and Naxos are excellent choices. You get the stunning views on Santorini and a more authentic Greek experience on Naxos.
Since you are planning this trip in late September early October for Naxos you should look for a hotel at St George beach. Its a good sand beach but is also part of Naxos town just a 10 minute stroll around the headland to the waterfront promenade.
Some images
Around Naxos town 2022 https://www.flickr.com/photos/stanbr54/albums/72177720299959098
Back to Naxos 2022 https://www.flickr.com/photos/stanbr54/albums/72177720299940917