Start small. Write a “slice of life” about an athlete, a volunteer – generally anyone who’s doing something for a reason. It doesn’t have to be something momentous or ground breaking: it’s just about a moment in their life. This is great practice for developing your skills.
Start with the person in action. Don’t start with background or establishing detail or any other sort of set up. Show the person doing something active: sitting and talking don’t count.
Capture details about the person and about where he or she is. Try to capture as many of the five senses as you appropriately can.
Try to answer the why: why is the person doing this, why is it important to him or her?
Quote the person, but never more than 1 or 2 sentences at a time. You should be trying to put as much as you can in your own words. After all, you’re the one trying to get better.
Don’t sweat the ending, although you can always circle back to something that appeared in your opening paragraph.
When you’re done, revise it. Cut it down by a quarter to a third. But understand that revision isn’t just cutting. It means rewriting to make your work stronger.
If you do this often enough, you’ll have learned any number of things about writing, not the least of which is not being afraid to ask people if you can write about them. You’ll also have learned many of the techniques that make any type of nonfiction interesting to readers. And you’ll have learned that to write well you have to write, period.