from what I've read, no. the only thing an existing udder can improve on is capacity with subsequent freshenings. however, weak attachments will make the udder droopier and droopier as well with subsequent freshenings.
only way to have better udders is to breed good udders into the babies. i'm dealing with small udder, small-ish teats and bad attachments on my girl, so i'm hoping to find a buck that can throw me better udders.
I mean, you can't really change human boobs all that dramatically, unless one goes for plastic surgery.....
I hope this helps...and those with more experience, please feel free to jump in!