Boil your beets whole until tender. (You can also steam or roast them whole too if that works better for you. From what I understand you will retain more nutrients that way too. I just find boiling easier.)
Drain them and let them sit in cold water until cool to touch. Then run cool water over them as you peel off the skins with your fingers.
Chop your beets into 1 inch chunks. Add salt, pepper, oil and cider vinegar and mix.
Add the herbs and/or garlic and finely chopped or crumbled feta and mix again.