I rarely experience writer's block, in the classic sense. I believe writer's block is triggered by fear.
As an athlete and as a business executive, I've found action is the best method of combating fear. So when I feel like there might be a block or I sense some fear, I take action and I write. I write until blue smoke rises from the keyboard. It might end up being rubbish but the action of writing stops the writer's block from ever gaining grip.
Now I must admit that my bigger obstacle is procrastination in the form of avoidance and distraction. I get lured away by the instant gratification of solving a problem, taking a meeting or playing with the kitty and forget the deeper satisfaction of staying seated and pounding out ten pages a day.