I have several techniques I employ whenever my creative process gets blocked. I make sure I have multiple writing projects I'm working on, whether self-directed or ideally a paying assignment. I also like to write in multiple genres so if I'm stuck on my current novel, I can write an op-ed piece just for fun, but always with the hope of getting it published. Or I'll make sure I'm working on a film script, either the adaptation of my own novel, IDENTITY: LOST, which I'm currently doing, or on an original screenplay. I've also dabbled with poetry a bit, although I think I'm awful at it. I have found, though, that the task of writing poetry does really help any writing process, making you get out of your comfort zone. That's why I think I admire poets so much, especially fledgling poets because I admire their tenacity to excel at their art and the process.
I also find that reading helps immensely. When I first started writing seriously on my debut novel I found that I began reading much more than when I was not writing. I also read all genres. I particularly like to read non-fiction when I'm blocked with my fiction writing. I find that it inspires me and helps me think of wild fictional scenarios for my thriller writing.
A long, slow walk also helps a great deal and is one of Natalie Goldberg's recommendations in her fine book about the writing craft, Thunder and Lightening.

I can tell you about my favorite writing "prompters." One has been the aforementioned Natalie Goldberg. Her seminal book,Writing Down the Bones, was a real eye opener for me about how to be an observer of life and write about it. Julia Cameron's Vein of Gold also helped me understand where and why I needed to dig deeper into my creative abilities. Marge Piercy and Ira Wood's So You Want to Write became (and still is) my textbook for the basics. Their writing prompt exercises were and still are immensely helpful. Another fun book I must admit I picked up completely because of its title, Novelist's Boot Camp by Todd Stone, proved invaluable not so much for the writing prompts it provided but for its no-nonsense, nuts-and-bolts approach to crafting your work.

NY Times#1 best-selling author Brad Thor, who so graciously provided a blurb for my debut novel, was discussing the art of writing for new writers the very first time I heard him speak. He said that when he first started writing he had always heard the long held mantra for new writers to "write what you know." He went a step further and recommends to writers to "write what you love to read." I have his words etched in my mind every time I put words to paper. I love to write stuff I love to read myself and that's what makes it so enjoyable for me.