I have never experienced writer's block. As a journalist, I never had time for it.
When I worked for BusinessWeek, I had to write an online story or two each day plus hone a pitch for the magazine--not to mention spend the vast majority of my day reporting. I could not sit and stare at my computer screen wondering how to write the perfect first sentence. I wrote an okay sentence, then another.
After I was done, I reworked the lede to be more attention grabbing. I tightened up paragraphs and replaced verbs with more active ones. I stripped out any passive voice. Most of all, I made sure that I was writing the truth as I saw it to the best of my ability.