I have a project, a really cute 9 yo mare who has only been a broodmare before now.
She is pretty smart, but kind of stubborn. She's lunging with tack now.
My biggest question is what is the best way to build up her topline and most especially her neck? Her neck isn't bad, but has absolutely no crest to it. Conformationally it is correct, but the bottom is thicker than the top. She hasn't been ridden ever, so it's not like she was ridden wrong. Her back end is pretty strong, and her hocks come way under and forward, but she's lacking in muscle behind the withers.
Suggestions for the best way to build topline and neck?
The best way to build her topline is to work her properly. I like using a chambon for horses with that underneath neck muscle and no topline. Just introduce it slowly, then lunge her in it until her poll is below her withers. Make sure she is forward (over tracking and the walk, tracking up at the trot). Don't ride in the chambon, however!
I personally don't like side reins for a horse like that because they can lean on them for balance, or learn to evade contact by going behind the bit. Sliding side reins are better, but the chambon is great because it only puts poll pressure on the horse until they put their head down, then it completely releases and the horse is free and has to carry themself.