Notes

Undead Settlement: By the burning tree with worshipping undead. This is to the left of the Undead Settlement bonfire, past the house
Road of Sacrifices: From the Crucifixion Woods bonfire head towards the Crystal Sage. Pass under the small bridge. The shard will be on the left side of the ruins near a fire that has two Lycanthrope.
Farron Keep: Go straight out from the starting bonfire. The shard is near a fallen tower guarded by slugs. (video)
Cathedral of the Deep: Right outside the Cleansing Chapel bonfire where enemies are praying
Smouldering Lake: On a body near a hole from the Old King's Antechamber bonfire. Look for an illusionary wall in the bonfire room. (video)
Irithyll Dungeon: From the bonfire, walk forward into the dungeon and turn right. Now go straight, head through the locked gate, and then drop down. Go right into the room and there should be a chest which is a mimic that contains the shard.
Anor Londo: In a chest on the first floor of the large dark room with the Deacons (before the Aldrich fog wall). Enter from the double doors and hug the left wall to find it.
High Wall of Lothric/Consumed King's Garden: From Dancer of the Boreal Valley bonfire, climb up ladder and go first left. Use the elevator and jump out halfway. Estus Shard is down the stairs to the right.
Lothric Castle: From Grand Archives bonfire, on the top of Lothric Castle near the Winged Knights. From the ladder that takes you to the Hunter's Ring you will see an archway that leads to a lower roof/balcony. Estus Shard will be found all the way out near the railing.