Use minimalist software that you are fairly confident that you could fix or recreate in another environment if necessary; for example, don't use gnome-screensaver but instead use slock. Where possible, use software suites where being future-proof is a first-class priority; for example, wherever possible use TeXLive. Consider something standards complaint with a rabid user-base over alternatives; for example, use Vim instead of Kwrite. (In fact, take a list of the packages in the current Ubuntu livecd, and the packages in the current Kubuntu livecd. XOR the lists. The result is a list of software you should not spent time building skills in if you don't want your skills to become obsolete in 5 years.)
Where you are not confident that you can pick something that meets any of these suggestions, pick the simplest software that you don't have to customize and that you will miss the least. For example, don't roll your own X window manager and don't use BerylFusion after setting three dozen options. Use firefox or chrome, but don't marry yourself to a combination of two dozen highly specialized extensions.
In an effort to future-proof my computer experience I follow these self-imposed restrictions. Additionally, I have a strict whitelist of software that I am willing to configure: zsh, vim, tmux, elinks (only because I could bare to lose it. It is not future-proof), urxvt (very begrudgingly, I only set my font and background color), and Awesome (very very very begrudgingly. The only configuration of it that I am willing to do is set my terminal to urxvt.) Any other software I use "as is", with the expectation that it could be obsolete and abandoned tomorrow.
Brief example of something that drove me to adopt this sort of attitude: I used to use Amarok to play all of music, and got very used to my setup. Amarok 2 came and wrecked everything, completely erasing all the mental effort I had put into Amarok over the years. Upset by this, I decided that life would be simpler if I just wrote my own very simple xmms2 client that I would never change out from under myself. This worked great for about two years until the breaking changes to xmms2 (requiring me to make changes to my client every few months) wore me down. Now I just use mplayer, a shell, and standard unix utilities. Even if I have to swap out mplayer I am confident I will never have to change my workflow again on a unix-like computer with keyboard.
This is something I obsess over.
Use minimalist software that you are fairly confident that you could fix or recreate in another environment if necessary; for example, don't use gnome-screensaver but instead use slock. Where possible, use software suites where being future-proof is a first-class priority; for example, wherever possible use TeXLive. Consider something standards complaint with a rabid user-base over alternatives; for example, use Vim instead of Kwrite. (In fact, take a list of the packages in the current Ubuntu livecd, and the packages in the current Kubuntu livecd. XOR the lists. The result is a list of software you should not spent time building skills in if you don't want your skills to become obsolete in 5 years.)
Where you are not confident that you can pick something that meets any of these suggestions, pick the simplest software that you don't have to customize and that you will miss the least. For example, don't roll your own X window manager and don't use BerylFusion after setting three dozen options. Use firefox or chrome, but don't marry yourself to a combination of two dozen highly specialized extensions.
In an effort to future-proof my computer experience I follow these self-imposed restrictions. Additionally, I have a strict whitelist of software that I am willing to configure: zsh, vim, tmux, elinks (only because I could bare to lose it. It is not future-proof), urxvt (very begrudgingly, I only set my font and background color), and Awesome (very very very begrudgingly. The only configuration of it that I am willing to do is set my terminal to urxvt.) Any other software I use "as is", with the expectation that it could be obsolete and abandoned tomorrow.
Brief example of something that drove me to adopt this sort of attitude: I used to use Amarok to play all of music, and got very used to my setup. Amarok 2 came and wrecked everything, completely erasing all the mental effort I had put into Amarok over the years. Upset by this, I decided that life would be simpler if I just wrote my own very simple xmms2 client that I would never change out from under myself. This worked great for about two years until the breaking changes to xmms2 (requiring me to make changes to my client every few months) wore me down. Now I just use mplayer, a shell, and standard unix utilities. Even if I have to swap out mplayer I am confident I will never have to change my workflow again on a unix-like computer with keyboard.