Keep writing. Try to do a little bit every day, even if the result looks like crap. Getting from page four to page five is more important than spending three weeks getting page four perfect.
I have a bad tendency to get rapidly bored with my own material, so rewriting is hard for me. I mean, I already know the story and would rather read something new.
Living gives you a better understanding of life. I would hope that my characters have become deeper and more rounded personalities. Wider travels have given me considerably greater insight into how cultural differences affect not only people, but politics and art.
I usually do one con a year as a GoH and try to make the World Fantasy Convention for business purposes. Last year I went to a worldcon for the first time in two decades. I may go again this year.
There's certainly more new SF available than when I started writing. That means there's also more bad SF available. Whether there is also more good is a matter for future historians of the field.
Besides the mistakes that are pointed out, I love the way readers become involved with the characters. When readers start asking about character motivations instead of concentrating on the special effects, it means you're connecting with them on a personal level.
Writing allows me the time to travel and see the world, which is what I always wanted to do. I'd really like to have been Sir Richard Francis Burton, but it's the wrong century.