Choose a multi-syllabic word. For example, memorize. Give yourself five minutes to list as many words as you can from letters in the word (such as me, memo, zero, ire, memoir, more, mere...). This type of exercise works on what psychologists call fluency - the ability to find a word. Generating as many words as you can in a limited time period challenges the brain to practice the word finding skill you need in that pause when you search for a word. Many word games lack that element of temporal challenge, and have not been shown to improve fluency. I still play that kind of word game too, but really just for fun.