Hi rea.
Seems like you had great time in our lovely island elafonisi is indeed one of the best beaches in the world. But is way too crowded and loses all the magic!
Unfortuantly the island is big and you need to spend a day to visit a beach. If you ever come to Crete again I would recomend to visit some not so well known beches such as seitan limani, kedrodasos, tripiti, domata, iligas. Some more well known is grabousa balos, falasarna and fragokastelo. Note that for a good not well known most of the times you need to walk a bit. The beaches are in chania.
Falasarna
Kedrodasos

domata tripiti seitan limani balos
Sorry if my comment is big, but as a Cretan i thought it would be helpful! Hope you come back some day