Personally, I found that my money dynasty league has made me much better at fantasy football as a whole because dynasty naturally forces you to pay much more attention to all the little things like situation, coaching staff, long-term QB outlook, which rookies will be productive this year as opposed to beyond that, etc. This is especially true in a paid dynasty league, as I want to win money and thus I need to do the research to put together the best possible team.
That's assuming you do some research, of course. First year of dynasty, I made a ton of mistakes and my draft is pretty embarrassing in retrospect. Wish I could go back and redo it with what I know now.
If you're in a few money leagues, I'd recommend finding a good fantasy podcast with a host that you like and enjoy listening to. There's no host who is going to get everything right, and you'll have to learn to trust your own evaluations of guys and be ready to fuck up from time to time. You're going to make mistakes. You're going to drop a guy who tears it up for someone else. You're going to make trades that come back to bite you sometimes (especially in dynasty). You just need to make sure you succeed more than you fuck up.