Start with a 20-minute introduction about the history and main information on the tower, so once you get there, it will feel like you know the place.
Then, skip the ticket line and head straight to the turnstiles to visit the Gothic clock tower on your own.
Every hour, two small trapdoors open and the twelve apostles march out to tell their stories. The Grim Reaper also rings a bell, checking to see whose time has come (unsurprisingly, everyone shakes their heads 'no').
There are also planetary motion, the zodiac, and more on the clock - and 75% of its parts are original, like 'from-the-15th-century' original.
Take the stairs or an elevator up the tower. From there, you'll have amazing views over the Old Town Square and the rest of Prague's Old Town.