When I first got my horse, his feet were AWFUL! He had been shod since he was a 2 year old, but I guess his previous owner decided she was done paying for shoes and abruptly had them taken off without any transition. He had thin, weak hoof walls, he was prone to thrush and abscesses, the walls always chipped and cracked, his soles were thin and tender... it was just bad.
I decided to take action against the issues by switching him to a low sugar, low starch grain, and adding a multi-purpose supplement with ingredients that benefit his hooves like biotin and Flax. That, and I found a fantastic farrier. I give him a lot of credit for the shape Riley's hooves are in now. He treats each horse individually, he doesn't trim them all in the same cookie cutter way. He knows what Riley's weaknesses are in his hooves and how to keep them balanced. He has corrected a lot, if not all of his issues. Riley's hooves look so great. No weird angles, no tenderness, they barely even chip anymore.
So, the moral to the story is, find a great farrier who can diagnose and treat your horse's hooves as an individual case, ask them explain things to you, give you advice... You will know if your farrier is worth his weight in horseshoes if he can give you honest, insightful answers. Also, balance your horse's diet. Add things that are good for hooves, cut back on the sugar. Just do some reading and make your decisions based on what sounds best for your horse. As we all know, each one is unique!
Good luck, hope my rambling helped! :)