Deliberate practice.

There's two main ways to do that.

1. Have a coach or someone who is good at the skill help coach those who are not so great at it.

2. Have some way to capture data that allows you to know how well you're doing. Page views, engagement rates, happiness of content, etc.

The best approach is a combination of both. But the generic advice would be "write a lot and promote the ability to write a lot" and you'll figure out the deliberate practice side out later.