JR Ewing of Dallas fame once accused a rival of being "all hat and no cattle". While it was a beautiful putdown, it was also just a variation on a popular theme. By one estimate, there are around 1000 popular all x a and no y insults in the English language, like all sizzle and no sausage (advertisers, take note), all bark and no bite, and all talk and no walk.
As with most popular word plays, the key for anyone wanting to create a new insult in this vein is to recognise the unwritten rules of the game. In this case, the main rule is to use either alliteration (bark, bite) or rhyme (talk, walk / hat, cattle). It's not a hard and fast rule, mind you, as attested by enduring pairs like all work and no play, and all mouth and no trousers. But look at these pairs and ask yourself which are most memorable: