Pay close attention to the tone of the conversation. Some paths require a more supportive approach, while others may require being more assertive.
Many versions of the game include a "Cheat Mode" or "Gallery Unlock" toggle in the main options menu.
Take a mental snapshot of the room's layout as soon as you enter.
Even with cheats, Christies Room has trap events designed to punish cheaters. Avoid these:
I can then provide the exact dialogue choices for those scenes.