Ksamil is a little sea village that turns into a busy resort in the summer. I was lucky visiting it in June, the weather was great, the sea warm enough to swim and there were not many sunbathers. June or September are indeed the best month to visit because later, Ksamil can get overcrowded. However very few foreigners ever make it to Ksamil so it still will have the local atmosphere.
The village of Ksamil is a bit messy with many buildings still under construction erected here and there with no planning at all. It reminds of South America a lot. Not all the streets have been paved yet but it all won’t matter when you see the sea and the coast.
The accommodation is ridiculously cheap, there is even one hostel in Ksamil where I stayed. It was neat, clean, simple and nice. The food is superb, the restaurants are mostly run by the families and the staff is very friendly.