Rinse the lettuce and swirl dry with a towel or with the lettuce swinger.
Peel and cut the onion in half, then slice thinly so that you get "half months".
Cut the tomatoes into 4 or 8 pieces (depending on the size)
Cut the olives into 2 or several slices. If you prefer a whole olive – that's also possible.
Cut or crumble the feta. Personally, I find a cube of at least 1/2 cm the tastiest. Larger than 1 cm comes across as rather clumsy.