I was wondering if anyone had any tips on common songwriting mistakes, it seems like the harder I try to write something, the worse it sound and the less inspired I become. I think with me the hardest part is creating melody lines that sound original. I have been experimenting with different chord structures with protools recording equipment. I did a general google search and came up with this good article but want to know if there is a goog book or DVD out there on the subject.

Smart Songwriting Tips- 8 Mistakes