(Say the word is "play". The next person can change one letter in the word to make a new word or they can add or remove a letter to change the word. If you remove a letter it is probably best to also switch a letter. Also, since the word is so small, it is probably best to add a letter or more. (Unless of course there seems to be no other possibility to change the word). So I could change it to "plays" or just switch a letter and now it is "slay". Or if you are feeling adventurous you could switch and add to get "delay".