I will begin with a simple Stables exploit. Pardon me if this is a repost as I had done a search and did not get any hits with this method.
To begin this process you will need a Mammoth mount or other large mount to get up on top of the stables.
Step 1. Inside the Stables is a stack of hay. If Facing the random bg buff it will be on your right side.
https://i.imgur.com/L7T2q5R.jpg
Step 2. Jump on to the wall in front of the stack of hay. Its quite easy.
https://i.imgur.com/iOSswPf.jpg
Step 3. Use your Mammoth mount or other Mount to jump and climb the wall. You will begin to land on the beam inside the Stables.
https://i.imgur.com/hKlKb7D.jpg
Step 4. Use your character to get in front of the window and jump up and into the window a bit. Will take a few tries.
https://i.imgur.com/5EWzSZZ.jpg
Step 5. Mount up on a Mammoth once again and jump up and move forward, back or whatnot to get fully on the roof. May take a few tries if you jump off the Stables.
https://i.imgur.com/MjQVNFo.jpg
Try it and have fun. I will update providing this goes well with how to get on top of the Lumbermill as well.
To include a picture of the Lumbermill trick and a place to begin the tactic.
https://i.imgur.com/IKPHlaW.jpg
PS. This works in RBGs as well.
Happy Hunting.