In my opinion, there are two main reasons to do writing prompts: either you are exercising your writing muscles to make them stronger, or you are creating new content to publish. Both are valid reasons to make writing prompts a regular practice.
Here are some of my own writing prompts, books that can inspire you, and links to other resources to help you keep writing every day.
For daily prompts, inspiration, and ideas, follow Kim Bongiorno Writes on Facebook.
WRITING PROMPTS & WORKBOOKS
Whether you have a specific project in mind, want quick ideas, or find feelings to be a great jumping-off point, these could suit your needs.
INSPIRATION & EDUCATION
The best of the best. Every writer should have these in print.
OTHER WRITING PROMPTS
There are countless resources for writing prompts. Here are a selection I have found useful:
Writer’s Digest writing prompt bootcamp
Think Written list of 365 writing prompts
Writer Igniter’s shuffling prompts rock so much
Poets & Writers has a few weekly writing prompts in an ongoing series
180 prompts here on Tumblr
Tumblr’s Awesome Writing Prompts
The New York Times has a list of 500 prompts for personal essays
31 days of writing prompts by TheBarefootWriter
Pinterest: follow writing boards like mine, or just search “writing prompt”
ON THE TOPIC OF PINTEREST
I believe writers should have a Pinterest account with two specific boards on it. The first is where you pin everything you’ve published (like this). This makes it easy to access and share your work. The second is a place for you to save posts you find about writing, whether they are prompts, books, advice, interviews with authors, or other resources.
There is also an option to have private/secret boards. If you are working on a new project, you can collect materials and pin them to this so as to refer back to it all in one place at any time. Name it the working title of your project, then pin images, research, comps, and the like to that board, whether you find them on Pinterest or elsewhere on the web. I find this a very handy tool for writing books.