The best beaches on Lefkada are located in the western coast where waters are the purest. The eastern coast has more villages than beaches and the water is not that clean. Kathisma and Kalamitsi were the beach beaches. Egremni was hard to get with all these stairs and Porto Katsiki was too crowded for my tastes.
Lefkada is soooooo relaxing and the good thing is that you don't have to plan your trip. You get into the car and just follow the road. All roads leave anywhere and in the crossroads just pick up a street, do not think more of it! By such a chance we got to the beautiful square of Karia and had an amazing Greek coffee under the plane tree. In Nidri, there are the most fun watersports and in Agios Ioannis you can do windsurfing and kitesurfing.
The hotel was in Agios Nikitas. a good centeal location close to the most gorgeous beaches and the capital town. Food is fresh and cheap everywhere, no need to worry about quality. I travel for many years in Greece and never had a food problem.