At the end of March I entered a daily Poem Writing Challenge for the month of April. Writing a poem a day can be trying and there's no real time for revising, but it's also invigorating and great discipline. After I post my poem on my Word-Painting blog I go over to the Read/Write a Poem blog and list a link for the day's poem.
The number of people responding has declined since that first giddy day when everyone posted a link. Thirty percent dropped by the wayside, but for those who have continued we're quickly approaching the half-way mark—well almost.
Read/Write a Poem blog lists prompts, but I've usually either triggered off them or totally ignored the prompt.
It's all about the discipline.
If you wish to be a writer, write. —Epictetus
nulla dies sine linea, never a day without a line
Here's a Prose Challenge 500 Words a Day or you can ratchet that up and do the 1000 words day challenge or the less demanding 250 words a day challenge.