These tools simultaneously aid me immensely, while keeping perfectly out of the way.
The blog itself is built on Octopress, a framework for blogging built around the Jekyll static site generator. An entirely-static live site cuts down on operational overhead, from the financial (hosting text is cheap) to the effort required (lower complexity, fewer securtity concerns etc.)
I use AWS for hosting: Route53 for DNS and domain management, S3 for the actual live content storage, CloudFront and ACM for SSL. Cheap, easy (given my experience), and capable of handling almost anything.
Byword is my editor of choice for drafting; both the MacOS and the iOS apps are great, and it just gets out of my way, so the only real barrier to me writing is me.
Vim is my editor of choice for, well, editing. I’ll generally write things in Byword (whether on my phone or my Mac), then later sit down at a terminal and paste it into Vim where I’ll clean it up and get it committed and pushed.