Here Are Six Common Phrases A Lot of People Get Wrong (but if people know what you mean, does it matter?)
1. Do you "flush out" an idea, or "flesh it out"? "Flesh out" is correct. It means you're adding substance or "flesh" to something. "Flush out" is when you make something leave its hiding place. Like flushing birds out of a tree, or "flushing out the truth."
2. "Chomping at the bit" or "champing at the bit"? Both are okay, but the original phrase was "Champing." It's when a horse grinds its teeth on the piece of metal in its mouth. Now we mostly use it to mean you can't wait for something to start.
3. "Set foot in" or "step foot in"? "Set foot" is the right way to say it. Saying you wouldn't "step foot" somewhere is technically wrong. Stepping is something you do with your feet, but you don't "step foot" anywhere.
4. "Hunger pains" or "hunger pangs"? Most people say "pains," so you'll get away with it. But it's really "pangs." It means a "piercing spasm of pain."
5. "Case and point" or "case in point"? Your case is "in" the point you're making. So it's "case in point," because they're one and the same.