Originally Posted by NYBanker
Might consider using an unlabeled container for your spirits. Many liquors are available in 375ml bottles, some of which are plastic. Removing the label and using one of these might not be a bad move.
Good luck with that one! 
I'm sure TSA would LOVE to see an unlabeled container of mysterious astringent liquid.
"Sir, you're going to have to drink some of that before we can let it through..."
"Okay"
"Sir, you're going to have to drink
more"
"But--"
"MORE!!!"
As stated above, you're allowed (by TSA) to carry unopened bottles of liquor onboard with no problems, and I've only once encountered a problem carrying a half-empty bottle through. Definitely wouldn't remove any labels.
Flasks are fine if they're empty... if there's anything in it at all, TSA will empty it into the nearest water fountain
.
FA's will serve you your bottle in F or BE. I've only tried drinking my own liquor own board in Y a couple of times and never got caught (I was drinking duty free which is definitely a no-no).