Staying in the beautiful village of Oia was on my bucket list - along with a million other people- but even in the midst of day trippers and cruise ship travelers there are still quaint and charming spots to be found.
In my opinion, the best thing to do is to head through the village in the morning and down the 240+ very steep and long steps down to Amoudi Harbor, past this charming church and all the donkeys and the stuff they leave behind...
We did it 3 of the 4 days we were there - both down and up. My waist line thanked me later in the trip and I ate Saganaki (to-die-for greek fried cheese) guilt free the whole time.
After you get down there, walk past the waterside taverns, over the rocky path and you'll be rewarded with this beautiful place to swim off the rocks, or jump off, if that's your thing.
If you're not the jumping type, like me :), you can gracefully launch yourself off these rocks. Can't promise the return climb back on will be quite as effortless. My favorite part was swimming over to the little rocky island. There you'll find a little church with a working bell. Notice the one guy in the middle standing? Depending on the tide, there are places where you can perch on rocks for a rest.
On your way back, you can have a late lunch at one of the taverns and enjoy fresh seafood and that fried cheese I mentioned.
Along the main drag of Oia there's one holdout who hasn't given over to all the shops. I saw her walking through the village one day in her floral housecoat. Made me wish I knew enough to have Oia on my bucket list in the 80's.