Don't leave dead companions or items you want to keep in any of the Tests. Once you've finished the a Test, you can't go back. (except the test of Love you can fly over with the magic carpet.)

Illusionary walls are common. If you're stuck right away, try walking on through, or try double-clicking on the wall.

Don't pussyfoot around in the Test of Truth. You can finish it in about ten seconds. Just watch the floor.

In the Test of Love, read everything. You won't need your weapons. If someone asks you to do something, do it. Everything you need to complete the test can be found after you enter the moongate. Near the Stone of Castambre is a hidden lever that opens a door in the passageway where you came in. Go down the passage and you'll find some cool weapons.

Don't take your companions into the Test of Courage. If they get killed, it's a pain to bring them back. Remember to take at least one glass sword. Keep moving and check bodies for useful items. Do not use magic on Dracothraxus. If you do, you won't be able to get the Black Sword.

Arcadion isn't as smart as he thinks he is. You'll need him.