What’s your Lego Harry Potter: Years 1 - 4 advice or tip?

One of the easiest Dark Wizard to unlock is Lucius Malfoy. Play the "Follow The Spider" level in Year 2 and unlock him when you fight the giant spider (you'll need the reducto spell).

Don't fret about shinny white objects, you'll get the reducto spell early on in year 4. Also, red shiny objects can only be activated by an dark wizard - which you should have access to during free play.

Red block upgrades you unlock and purchase need to be enabled each time you start your game. Pause the game and select the Extra's menu.

Shoot items repeatedly until they stop reacting (such as giving coins, or shaking/moving). For example, the gold knight statues you'll encounter early on take 6 or so hits until they break (at which point you can put them back together)

You can't unlock everything your first pass through. You need to play each level a second time in free play mode so that you can use spells and characters you'll unlock . For example, in story mode, you might need to dig to unlock a brick but you'll only have access to a digger once you play in free play mode. Its generally better to wait until you've completed the game in story mode before playing in free play mode - since you're guaranteed to have access to all your spells and characters.

Ghost Stud bring in 1000 each, so you'll recoup the cost (99 000) of unlocking it quickly.