It depends. I don’t get writers block writing web content. Creative writing is a different story. These days I don’t have any time to write creatively. However, I did used to have some cool ways of overcoming a creative dry spell.
I used to always get stuck writing dialogue. It would sound stale. In this case, I ended up going to cafes and bars with my tablet with the intention of looking like a trendy Starbucks freelancer. What I would really do, though, is listen to people talking around me and type their conversations.
Basically, I was literary voyeur in peoples lives. Naturally, you have to be discrete. However, you can come away with some great conversation templates and ideas which you can use to enrich your writing and make is sound more natural.
Plot problems are a different kettle of fish. My rule these days is to simply murder someone or have a horrible calamity happen. i.e. If i’m stuck not knowing how to proceed when I have two or more characters in an otherwise boring setting, there will suddenly be a gas explosion nearby. Then you can pad out your whole creative world by creating lots of cool little story arcs, etc.
Once when I was stuck, I decided to have the protagonist of my story saw her nemesis’s hand off with a bread knife. She had been a very sweet woman until then and it was completely out of character, but it worked. (Of course, it helps that I write sci-fi/crime/horror.)