This is the process I go through when writing a serious story.
- Conceive of an idea. This is almost never something I do purposefully; ideas come to me, I don't come to ideas. I ask myself if it good enough to be made into a story, and the answer is usually 'yes' unless I cannot come up with an actual plot.
- Write down a summary and which characters will be included. The summary is brief and concise; one sentence at first, then an extended paragraph that describes all the events in order.
- Write a draft. This is usually the longest part, although I do still try to do it quickly. A draft just has to make enough sense so that you understand what's going on.
- Editing begins. Cut out necessary sentences or phrases, add things I missed, change words, everything.
- Proofread- make sure there are no remaining errors and I didn't leave anything out. When the story is safe to be read to my English class without me blushing, it's done.
So as you can see, writing a creepypasta (or anything else) takes planning and effort if I want a good result. These steps are not all strictly necessary, but it's a good idea to do all of them if you're going to begin a creepypasta, especially for the first time.