Be careful setting explosive timers so that everyone in the party knows how much time they have. Especially if you've taken any lessons from James Bond in Goldeneye.
Han: We ambush them when they come out.
Trooper 1: That's a lot of pizza delivery guys.
Trooper 2: Bags the pepperoni!
GM: Your trick works by the grace of having dozens of combat-hardened Ewocs on your side.
Leia: Right, back to the plan.
Han: Great! I'll finish placing these explosives. Chewie, gimme a hand.
Chewbacca: We should be careful.
Han: What could possibly go wrong while placing explosive charges in an enemy base?
Han: 30 seconds is long enough, right?
Chewbacca: Long enough to find a ship and take off? I'm not entirely sure about that.
Han: Find a ship?
Leia: You know, our actual plan.
Chewbacca: Tell me you didn't start the timer.