Ask HN: What does your development process look like?

I'm curious how others go about their actual development - both the tools you use, the environment you work in, and how you actually write and test code. I work a lot in HTML, CSS, and Javascript, relying on React and Meteor frameworks, and using Sublime Text 2 as my text editor. Most of my work is building new projects from scratch vs editing existing code bases. I tend to write 3-5 lines of code, save, reload, and test manually to ensure everything is working fine. This seems slow at times, but I feel like it reduces the time I need to spend debugging later on. I haven't found a lot of value in automated testing until the project reaches a certain size where most of the requirements, design, and code architecture has been stabilized. I try to keep my code as modularized as possible as well vs optimizing for DRY principles to avoid changes in one part of my project affecting other parts unknowingly (where automated testing would be useful). I realize for large projects where codebase and loading times are issues, this trade off is reversed. What does your development process and environment look like?