There's ONE basic skill in writing that can help all writers, everywhere, anytime. I firmly believe this.
That skill is... LIST MAKING.
Making lists can help your writing. All your writing. Any piece of writing.
1. I don't know what to write - I make a list.
2. I want to organize what I write - I make a list and move pieces around.
3. I want to categorize what I write - I make groups of lists.
4. I want to change what I write - I make a list of possible options, alternate titles, synonyms, etc.
See.... list making is essential to every major kind of writing. I prefer lists to webs for brainstorming any day. Lists are linear - you can look back and see how one idea led to the next... you can follow the path. With a web, your ideas end up all over the place, and looking back, it's not always clear what you were thinking when you went from one idea to the next. With a list, you can backtrack and add on, because you can clearly see the connections (I suppose a Tree would also be a form of list making with extensions, but much more organized than a web).
Whenever you need to write ANYTHING, make a list to get started, organize, categorize your thoughts. List making can help you start and finish any kind of writing!