Education is important. I had been out of school for umpteen years before I started my first novel and frankly, english wasn't tops on my list of priorities during my academic endevaors. I didn't realize how much I needed a refresher until I had completed it and started getting feedback. So I took a creative writing course at our community college. I really enjoyed it. And the saying 'you can't teach old dogs new tricks is bull. I was the oldest student and got an A-, the highest grade in the class. (The dufus teaching the class told us he didn't believe in giving A's.)
Beta readers are also very important to your project. Relatives are nice, there's only one problem with them. By nature, they don't want to hurt your feelings. You need people who will will be truthful. That's where a writers group comes in, and not just any writers group, but one that critiques.
I can't stress enough how important this is. The critiques, not just on your work but on other writers material as well, is invaluable. I think the biggest satisfacation I get out of belonging to the Henderson Writers Group is the improvement and increased confidence I see in our members. It's awesome to see.