I choose answers that only barely make sense. ie...
"Where is your favorite vacation spot?"
Narnia
"What was your first pet's name?"
Falkor
Even my closest friends who know me would never guess those, even if they knew I was giving bullshit answers, simply because I was never into "The Lion, The Witch, and the Wardrobe" or "Never Ending Story".
(Note: These are not ACTUAL answers I've given, but you get the idea)
I save the bullshit answers into my password manager. But yeah, it's probably a better idea to just use an actual pass phrase.