So this isn't exactly only about pit bulls, but I'm posting it in the pit bull talk section anyway.
I often say that I've made a lot of mistakes with Renee that I don't want to repeat with my next dog. There are also some things that aren't necessarily bad, but that I want to do differently with my next dog. I think some of them stem from Renee being an only dog for so long. Now that I live with three dogs, there are certain things that are more annoying than when Renee was an only dog. (Note: Renee is still my only dog, but each of my two roommates also has a dog.)
One thing I want to do differently the next time around is to get the dog more comfortable lounging on dog beds or the floor. Renee has a hard time settling if she can't be on the couch. So much so that I end up giving up my spot on the couch just so she'll relax. My roommate's dog Geno loves to lay on the couch, but he's also quite content to curl up on a dog bed or the floor if the couch is occupied, and it's very nice.
Another thing is to embrace a puppy's desire to put things in their mouth. I made the mistake of punishing Renee every time she picked up something that wasn't hers (and she's a shepherd mix, so she's very mouthy). I think that has a lot to do with how much I've struggled trying to work on a retrieve with her. I took a different approach with my parents' dog Hannah and she's a retrieving fool. Of course, she's also most likely part Lab, so I'm sure that helped, but still.
What things will you do differently with your next dog?