William Archibald Spooner, a British clergyman and educator had to speak in public. Because of nerves, his tongue got tangled. He would say things like "a blushing crow" when he meant a "crushing blow." Spooner's letter reversals because legend and gave listeners a laugh. By 1900 his name inspired the word, spoonerism.
Consider transposing words and play. Imagine signing flosser for flying saucer. Try having a Tun Fime. Get into a doyful jay! Let your tang tungle.