If you've played any previous Harry Potter titles, then in comparison, Deathly Hallows Part 2 is considered the most challenging, mainly for its playthrough on Expert mode. Still, not difficult enough to warrant more than a 2-star rating.

The bare minimum number of playthroughs required is 2, plus a completion of challenges. More likely, however, you may end up doing three, possibly four playthroughs overall. Expect about 20 hours of gameplay on this one.

First, you have the option of playing on either Normal or Advanced. The main difference, is that Normal provides a high aim assist, while Advanced will prepare you more for your future Expert playthrough. The trophies are stackable, and both will unlock the Expert mode, so the choice is yours.

Either way, follow one of the walkthroughs or collectible guides under our Links tab during your first playthrough, to find all characters, music tracks, and other items. Don't fret if you don't find them all, as you'll have at least another playthrough ahead of you. Plus, there's one collectible which you cannot get until your second playthrough anyway, as it requires the Apparate spell in Chapter 2.

Also, aside from finding collectibles, you should also focus on the spell and kill-related trophies. Check out the trophy guides under our Links tab for further details.

Once that's done, you will have unlocked Expert. Go ahead and start your next playthrough. As tough as this may be, this is also your chance to unlock any other trophies you've missed thus far, and find the remaining collectibles.

Next are the trophies related to the 12 challenges, which you will need to beat all with a gold rank for the Shining Example trophy.

Last, is mopping-up for any other trophies you may still need at this point.

First, IGN has a Walkthrough, here:
http://www.ign.com/wikis/harry-potter-and-the-deathly-hallows-part-2/Walkthrough

And a video Walkthrough, on Gamerfuzion:
http://www.gamerfuzion.com/harry-potter-and-the-deathly-hallows-part-2-walkthrough-strategy-guide-xbox-360-ps3-pc-wii/

Godchild1020 & AndrewAnonymous have a great Trophy Guide, here:
http://www.playstationtrophies.org/game/harry-potter-and-the-deathly-hallows-part-2/guide/

And a detailed Trophy Guide here, created by DaveyHasselhoff:
http://ps3trophies.com/forums/showwiki.php?title=PS3-Trophy-Guides:Harry-Potter-and-the-Deathly-Hallows-Part-2-Trophy-Guide

And a great Trophy Guide here, by Hoagie324:
http://www.playstationtrophies.org/forum/harry-potter-deathly-hallows-part-1/79238-harry-potter-deathly-hallows-trophy-guide-road-map.html

Josh Romero has a few Trophy Guide videos, here:
http://www.videogamesblogger.com/2011/07/13/harry-potter-and-the-deathly-hallows-part-2-achievements-trophies-guide-xbox-360-ps3.htm

This is a useful Collectibles Guide, by Godchild1020:
http://www.playstationtrophies.org/forum/harry-potter-deathly-hallows-part-2/115867-harry-potter-deathly-hallows-part-2-collectible-guide.html

And here's a Challenge Mode Guide, also by Godchild1020:
http://www.playstationtrophies.org/forum/harry-potter-deathly-hallows-part-2/116109-harry-potter-deathly-hallows-part-2-challenge-mode-guide.html

Lastly, here's a basic Trophy List:
http://www.playstationtrophies.org/game/harry-potter-and-the-deathly-hallows-part-2/trophies/