First, I am not even sure what exactly NLD is - I only noticed that I have deficits/problems that are additional to my ADHD, (other ADHD people don't have them), I didn't see any possible source for them, they are quite severe and disabling, and quite fit into the descriptions of NLD I found online. With that said, here are some things about what I see as NLD.
I have found reading books to be helpful. A certain book was particularly helpful - however, I do not want the title posted here, but I would love to PM its title to anyone. It is an unusual book, and quite complex, but extremely good. Also, I've noticed that people's NLD generally reduces as they age - not just from 15 to 25, but I think even from 40 to 50, where their brains are supposed to get slower. This observation is based on a very small sample size. This probably happens because real life forces them to use the part of their brains which involves NLD, and I hypothesize that using that part trains it - like pushups for your brain - not because that makes intuitive sense, but because that works for other things, such as working memory.
P.S. May I PM you to ask you a few questions about your NLD? I am trying to invent a way of figuring out which people have it and which don't.