I have been writing for a release, all my life. And as a necessity to write to my business associates very early in my career I started formally fine-tuning myself for business writing with help of my sibling who teaches business communication as a subject in his university. I found myself improving in time till I did not need his mentoring anymore.
So yes one can learn to be good at writing.
Attributes for a good writer is the same as an artist: My full-time activity is Creative arts.
Here are my points:
1. Remain empathetic, tolerant & compassionate to world affairs and beings around you.
2. Derive pleasure in little and simple things of life.
3. Maintain a journal.
4. Research on the truth, report the truth one believes in.
5. Develop literary language skills
6. Develop a passion to read.
7. Be willing to perceive from the other persons point of view. (put oneself in the others' shoes) in order to analyze all sides
8. Get fully immersed in an experience.
Well these are the main attributes at least which has worked for me. :o)
The main thing is to keep in touch with writing. And you will be a good writer.