Do four minute lists* of your own invention or use these: words pertaining to drainage; words starting with Th; words that get stuck in your head; names for secret hideouts (real or imagined).
* MINUTE LISTS are a language brain warmup. For each list item, set the timer for one minute and write as many words as you can think of in that item’s category. Write at speed and take anything that comes to mind, even if the words popping up are incorrect matches or not real words. The speed and free-for-all ethos are aimed at getting your vocabulary moving.