Hi,
I work as a web developer and a designer, I'm not going to lie but I'm not an artist or that creative

I need some help on how to give my designs a better look

Today my manager told me 'hmmm.. your designs are okay but they miss the wow factor' and I really need help with that
What should I do to be better ?
What should I do to train my eye so they choose better colors ?
What should I do to make my designs pop out ?

Thanks...
@JR I'm not a 'hardcore' coder, I just code with the average level
And the company I'm working with was in need of a designer so I guess I will be more of a designer

But the question is, Is it a gift you have it or you dont ?
or with practicing I can be good ?