they will start popping up, just explore. I finished the game and overall have 10 estus flasks and +5 upgrades on them... --- Official Lightning's shorts and Selphie's panties of every board. Official Kairi's panties and Aqua's shorts of KH3 board.
One is in the mansion in Majula. You get the key to the mansion by talking to a cartographer NPC several times. I believe he was located in a section of the Forest of Fallen Giants. --- "Its not assuming when there's evidence all over the internet buddy. But nice try." - kalipou7
Majula 1: Hit the rock on the edge of the well near the big manor. Majula 2: In the manor mentioned above. In the basement. FoFG: Go up from the Cardinal Tower bonfire. Smash the door. There will be one in there. Lost Bastille: In a corridor of the first courtyard. Shaded Woods 1: Behind the locked door underneath the Giant Basilisk. Requires Fang Key (acquired from petrified monster down the tunnel). Shaded Woods 2: Room opposite Old Akerlarre bonfire. No Mans Wharf: In a house near the lever for the ship.
There are more as I'm up to 9, but I don't remember. --- PSN:PhadedWun Lurking in the Shadows..