Building a writer's toolbox

I'm calling this my Toolbox Post #2 because I recently wrote about a dancer's toolbox on my ballet blog and it made me think about writers and how they have toolboxes too.  While most of a dancer's resources come from classes they take and corrections given to them by teachers, how do writers get theirs?  I can think of 3 ways:

1. High school and college courses: This is where a writer gets her flashlight and her hammer.  You know, the basics of craft, such as -
--Three act structure.
--Grammar.
--Literary devices like metaphor and simile.

2. Writing workshops: This is where a writer will get her needle-nose pliers and snake, items that are more specialized for different uses.  It could be during a one-day or week-long course that addresses a specific issue, such as -
--Writing in genre.
--Publishing and agenting.
--Rewriting.

3. Reading: This is where a writer will find her tubing benders and pipe extractors.  What are tubing benders and pipe extractors, you say?  "I didn't even know they existed!" Exactly!  That's the reaction you have when you read books by authors who approach storytelling in new and exciting ways.  That's the moment when you say, "I didn't know I could do that!" Such as -
--Unreliable narrators.
--Multiple POVs.
--World-building.

As I said in my ballet post, when you have a leaky faucet, you get out your toolbox and you fix it.  And when you have a book that's got plot issues or pacing or structure problems, you do the same thing.  Diagnose the problem and fix it.  No wringing of hands, no pouting or running away.  A plumber doesn't get upset when the pipe is broken and neither should you.