If it's my daughter, I calmly confront her and let her know why I think she's not telling the truth.
If it's anyone else, I shrug, and thank my lucky stars that I have been around the block enough times to understand that generally, people can tell when they're being lied to. I don't think confronting is the wrong tactic, but I'm tired, and personally not willing to be angry over someone else's dishonesty at this point.
If I'm lying, I mentally beat myself up about it.