I started writing plays because I did an Arvon course - something I would highly recommend. Douglas Maxwell was one of the tutors and he had lots of very wise things to say about bring a playwright. This included being an expert on what you were writing on. Not just on the facts though, on the emotions.
It was a real breakthrough for me, this idea that you had to have an emotional connection to your work. That it's the only thing that gets you writing, and keeps you writing, and makes you write well, or at least as well as you're able to.
Lots of my writing is about hurt, disappointment and anger. The thing is, I'm not relentlessly miserable. (Except when I listen to the Today programme and shout at the Tories.) But these emotions are all in there, and they're really good places to write from. Even comedy. Especially comedy.
I thought of all this because I was browsing the t'internet in my perpetual quest to waste time and I came across some more of Douglas's advice, and it's all pretty brilliant, and worth a read. So do.