Collect the handgun shortly after the starting. When at Norman's house, find the room where he stores his hunting rifles. Put the handgun next to the other weapons. Note: This is mutually exclusive to earning "Eraser", as you will no longer have the handgun.
This ending requires the kitchen knife. If you wake up and do not have the knife, it can be found in your house. You must choose to cut your wrists in the bath. After waking up, investigating the remaining clues, and getting the knife again from the basement, go upstairs to the bathroom and watch the ending.
Release the mouse that is trapped in the mansion where the game starts. When on the first floor, you will find a door with tape on it. Open it and go to the table. You will see the mouse again. When it sees you, it will retreat into its house.
Towards the end when find a pile of dirty rags in the secret room, choose the option that says it contains the body.
Answer "No" when asked if it was Rachel's dead body inside the bag.