Press the crosshairs button to highlight all the interactive hotspots in the current room. Invaluable, as some important items are almost invisible.
Hint button
The hint button is your friend. Once used, it will only be accessible again after you have tried a few new item combinations.
Point and click
It is a (particularly obtuse) point-and-click game, so talk to everyone, try to pick up everything, and if in doubt, use every item on every other item.
