Always have an alibi. It helps if it's the truth, but it helps a lot more if the truth is actually believable.
Jabba: You weak-minded fool. Han Solo regularly went hours without shapeshifting!
Han: I can do that too!
Han: No, wait...
Han: Look, it's not me. The accent is fake! See!
Han: I've been stealing identities from other people for years! Ever since I killed Alberto, who was a serial identity thief!
Han: It's simple.
Han: Obviously in this period that I don't remember because I have amnesia, I must have stolen the identity of this "Han Solo" shapeshifter person.
Han: Everything bad that you think I've done must have been done by the real Han Solo.
Boba Fett: Not so! You were in cahoots with Obi-Wan Kenobi. Whoever you are, it's you I've been tracking.
Han: I have no idea who you even are!
Boba Fett: That.
Boba Fett: Proves.
Boba Fett: Nothing.