Examples:

• Yeah, well a little heads up would have been nice.
• Next time, answer your phone if you want a heads up.
• Yeah, all right, thanks for the heads up, Harry.
• Just a heads up, traffic in the family room is horrible.
• Not so much as a heads up to me.
• So, just a heads up, I'm starting the rampage now.
• Want to give me a heads up, let me know what I'm looking for?
• Just a heads up, I might vomit; where's the nearest bathroom?
• Uh, heads up, they're all in the hallway now.
• I came here to give you a heads up.