Here's the best advice to be given regarding songwriting...never stop writing music. If you compose consistently, you will only keep improving.
Songwriting is a beautiful art. However, it is also a learned art. The more you write, the more you'll get a feel for your own original style. I think it's safe to say that nobody wants to be unoriginal. So keep writing until you find out who you are musically and where you want to go musically. Once you get to that point, writing songs will become ever more fulfilling for you.
Good luck with your songwriting endeavors. Lock in your inspirations, then go write the best songs in the world...and no, I'm not kidding.