Take the usual road as far as the old bridge and Taverna Gefyra, go past the Taverna and follow the long bumpy track which has occasional useful signs saying preveli rooms and palm beach. Eventually after an interesting bouncy and dusty journey you will reach Drimiskiano ammoudi beach. Do not bother with Preveli Rooms, but try Dionysos Tavern instead ( try both if you like but I think you will prefer food, setting and friendliness).
There is a good path directly from the Taverna to Preveli beach and another from the large car park of Preveli Rooms. A much better way to walk to Preveli beach, not long and far better than the 400 plus steps down from the Preveli beach car park.
You can also rent a pedalo to make the journey from one beach to the other.
A few sunbeds and enjoyable swimming from Drimiskiano ammoudi beach.
There is also a good unpaved road along the coast from here to other beaches.
Website with photos of path and Taverna http://prevelicrete.com/index.php/latest-photos