On a Recent F flight to JFK I found the pygamas and slippers of the previous occupant under the companion seat which had obviously been missed by the cleaners. It didn't affect my flight and I discreetly pointed out the offending items to the excellent member of crew who was looking after me and asked that the cleaning companies management were made aware of the error. Whilst the crew member and the Csd were horrified I reassured them that this was the end of the matter as far as I was concerned. I then slept for the remainder of the flight, to awake to find the offending items had been replaced by a bottle of LPGS as a thank you for my understanding. I have experienced missed cleaning on several other airlines but as C.W.S points out, slips like this like this happen, it's the service recovery that matters to me.