It's no surprise that I spend a lot of time in Emacs. Especially when I'm developing software, either for work or for personal fun, most of my time is time spent in Emacs. While I do obviously flit over to Chrome, and mostly do my CLI stuff in iTerm2 (I really like eshell but it just can't replace a good terminal for me), I spend a lot of time looking at Emacs.
Here's what my Emacs looks like:
Key elements for me are as follows:
Light background
Something I've never really got on with when it comes to code editing is dark themes and dark backgrounds. I find it too much of an eye strain. Oddly, I tend to prefer dark themes everywhere else, but not when it comes to working in Emacs. The theme I use is the built-in adwaita theme.
Less boring mode line
I make use of powerline to make the mode line a bit less boring-looking. While the colour scheme is such that it's kept in line with the light look, the style is nice in that it sort of matches the style of prompt I use in my shell.
Full screen
I always run Emacs as a full-screen application, then splitting it into different tiled windows using its own internal window handling. This is something I've done from way back when I got started with my first GNU/Linux desktop machine, and still like to do on macOS.
I also run Emacs as a server and then use a little wrapper around emacsclient to open files (both locally and remotely) from the command line in that Emacs session.
Comfortable eshell when I need it
Although I say above that I generally don't use eshell, preferring to use a full-featured terminal application, in combination with fish, I do sometimes dip into eshell for quick things. So of course I have that configured to feel comfortable too.
I do this easily thanks to eshell-git-prompt.