My current design philosophy began with the above toolbox.
The toolbox in question belongs to Adam Savage, who you probably know from Mythbusters. Adam built the toolbox when he was working at Industrial Light and Magic as a model maker. Impressing his coworkers was the main impetus for creating the box, but he built it with a certain design philosophy which he calls first-order retrievability, and that is why I love it.
I don't know if Adam coined the term, but he has certainly popularized it. Googling "first-order retrievability" will give you page after page of people trying to replicate the toolbox.
The whole idea behind the concept is efficiency. If something has to be moved in order to get to something else, that lessens efficiency, and slows you down. It's not intuitive. If you design something with a first-order retrievability mentality, you are ensuring that everything is out, visible and easy to use. Adam talks about his process of reorganizing his personal shop using this mindset in the video below. (I've fast forwarded to the good part for you.)
I've heard of others designing with the first-order philosophy. Casey Neistat has set up his movie studio to be as easy and convenient to use as possible. He told Gizmodo the reason for doing this, like Adam, is primarily speed. He even goes so far as to leave all his power tools plugged in so they can be used at a moments notice.
Taking it further
Neither Casey nor Adam are web designers. The first-order concept only applies, for them, in the practical design of their work spaces. I want to take the concept out of their shops, and apply it to the internet.
When designing things, I want to organize them for speed. For instance, I am constantly finding myself waiting on my phone when I want to take a Snapchat. I'm usually taking a snap because the particular moment I am experiencing is funny/interesting, and I want to share it with friends. The process of unlocking my phone, hitting the home button, choosing Snapchat and then waiting for it to load can be made faster with a better processor, but it can also be made faster with fewer taps.
In other areas of design, the same idea can be applied. When going to a website, I usually want to get to content as quickly as possible. I don't want to faff about in bloated, unnecessary menus before getting to the content I visited the site to read. Everything should be as efficient to use as possible, even if it means your website lacks the artistic flair necessary to make it into a 21st century Louvre.
In recent web design projects, I've been trying to keep this concept in mind. No unneeded taps, nothing hidden behind three horizontal lines that doesn't need to be. Imagine pulling your phone out of your pocket and having a button on the lock screen to open Snapchat directly. Apple did this with its camera app, and the functionality is great. Less swipes, taps and gestures to get to the same place means more of the funny moments I want to share make it to my friends.
Of course, there will always be a need for menus, sub menus, even unhelpful lock screens (on occasion.) But considering first-order retrievability, even giving a name to the idea of simplicity and efficiency in design, is extremely helpful. It has proven to work well for Adam and Casey, and I don't see a reason websites and apps can't take the same principles to heart in order to maximize and streamline the time we spend with their products.