I didn't do a very good job of it, did I

Left me baffled. If you don't know what talk he talks how do you know what talk he walks?

There's gonna be some context here; this isn't the sort of thing somebody is just going to pop off with. Folks who use this phrase know what the walk and talk is referring to. To me, wtw & ttt means that the person referred to knows what he is doing and does it. Practice what you preach is more or less the same thing.