There are 9 Demon Doors to be found in Albion, arranged alphabetically. If you have already opened all 9 doors before downloading "See the Future", you will get the achievement when you load the game with the DLC for the first time.
Near the entrance to Bloodstone from Wraithmarsh, amongst the sepulchers. Play the Lute for the door until it asks you to stop, then stop on green.
Take the left fork on the road to Bowerstone. You need the following expressions to perform in it's play: Bloodlust Roar, Blow Kiss, Dance, Fart, Growl, Laugh, Middle Finger, Point and Laugh, Vulgar Thrust and Worship.
Follow the main path, on the right.
This door wants meat, so kick some chickens into it.
Near a wetland area in the south of Brightwood.
First it will ask you for some cheese. After coming back with cheese, it will then make more demands: You must wear either dreadlocks/mullet, muttonchops/handlebar moustache, Bandit Bandana/Yokel Hat, Tart Skirt/Noble Trousers, and a Noble Gent's Shirt/Corset.
Take either of the side paths under the castle stairs.
Open all the other doors first.
Near the beach.
Bring someone to the door and use the Propose Marriage expression.
On the main path.
Your Dog must perform 5 different tricks.
You must have at least 50% corruption to open this door. Try raising the rent or eating yummy food.
Near the warp point for the area, you must bring it an audience to watch it's play. Bring as many as you can, I got a bunch from Bloodstone and it worked fine.