This game is, by far, arguably the easiest Platinum available on the PlayStation 3. We at Trophy Hunter had fun trying to obtain the Platinum in the quickest time possible. So far, the record is 3 hours and 42 minutes. See if you can beat it.

Start with the tutorial and learn the dance steps; they're easy enough to gain a perfect score for each song during the game. If you mess up, thereby not acquiring the trophy, don't panic - you can replay them from the Title Screen and still get the trophy.

Riding Blue Jeans is incredibly tedious, but necessary in acquiring the Champion Rider trophy. Unfortunately, you'll have to ride that horse many more times after that, for it's the easiest way to gain cash, which you'll need to purchase clothing for the Big Spender trophy. Anytime you enter a shop, buy every piece of clothing you see - and keep checking back, as new outfits will appear during the course of the story.

For the Fashion Designer trophy, buy only ONE stamp, and save the rest of your money for clothes. Then, when you're in the trailer, just go nuts with that one stamp on every piece of clothing you have, until the trophy is unlocked.

Also, the first time you enter the fair, don't worry about playing any of the mini-games. You'll HAVE to play them later as the story dictates, so wait until then to unlock the fair's mini-game trophies, just to save some time.

Here's a great Trophy Guide, by pretend_hero:
http://www.playstationtrophies.org/game/hannah-montana-the-movie/guide/

And a detailed Trophy Guide here, by Burn:
http://ps3trophies.com/forums/showwiki.php?title=PS3-Trophy-Guides:Hannah-Montana:-The-Movie-Trophy-Guide

Here's a basic Trophy List:
http://www.allps3trophies.com/retail-games/hannah-montana-the-movie-trophies.html