It's important for some children to have direction during their writing times, and even for those who are avid writers with tons of ideas word lists go along way to supporting their efforts. Typically I complete word lists with the whole group as a mini lesson prior to a Writer's Workshop period. Word lists are important because they provide children with the spellings of key words that they may use while completing a writing project related to a theme or a particular season. As well, various words may serve as a catalyst to creating a great story.
Gather the children as a whole group and tell them that you want to create a list of words that will suit, Halloween time, for example. Tell them that during Writer's Workshop they may want to work on a story related to Halloween because it's that time of year. Ask them to think about what words they might use in a story related to Halloween? Also, remind them that their words can relate to the season during which Halloween falls to ensure you get seasonal words as well. Some children may simply want to do a seasonal story. Go around the room choosing children one at a time to share their words. As they share, add their words to a large piece of chart paper that can be displayed prominently in the class for children to refer to later.
Examples of words children may suggest may include witches, pumpkins, graveyard, leaves, goblins, monsters....If children suggest a word like "bat" I may tell them it was a good suggestion but that because most of the children can spell the word "bat" I'm going to leave it off the list. The finished list should ideally include words children may use, but may also spell wrong in their writing. The completed list is a reference, and that is the point that should be highlighted in discussion.
Teachers should make theme lists often for all occasions, including science themes, holidays, seasons, etc. To model the use of the word lists I will usually write a story during a modeling time specifically geared toward the theme so I can use some of the words on the list.
Happy Writing!