It's not always clear what are guests amenities which you should leave in the room (sound machines, alarm clocks, hair dryers, blankets, pillows, towels etc) and which amenities you can throw in your suitcase at the end of your stay (soap, individual shampoos/conditioners, pencils, note paper, postcards (remember those?) Q-tips)
Sometimes we're not quite sure if we can take things or not. (bath bombs, bath salts, spa scrub brushes, tote bags, sun tan lotions, coasters fall into that category