Have a look over on my other blog http://jlpwritersquest.blogspot.com/ for tips on what I find helpful when writing articles. I'll be posting some tips that I find useful when writing short stories over there soon.
I haven't sent may pitches put recently as I've been in short story mode but I'll be continuing with my Writers' Bureau Journalism course shortly and so I've been looking at new ideas for that and it made me think about the advice I've been given and what I've read that's helped me since I started writing articles. I hope it helps you too.
Let me know if you've had any success with your articles or if you have any tips of your own.