I use non-Unicode mode in the terminal emulator (and text editors, etc), I use a non-Unicode locale, and will always use ASCII for most kind of source code files (mainly C) (in some cases, other character sets will be used such as PC character set, but usually it will be ASCII). Doing this will mitigate many of this when maintaining your own software. I am apparently not the only one; I have seen others suggest similar things. (If you need non-ASCII text (e.g. for documentation) you might store them in separate files instead. If you only need a small number of them in a few string literals, then you might use the \x escapes; add comments if necessary to explain it.)

The article is about in JavaScript, although it can apply to other programming languages as well. However, even in JavaScript, you can use \u escapes in place of the non-ASCII characters. (One of my ideas in a programming language design intended to be better instead of C, is that it forces visible ASCII (and a few control characters, with some restrictions on their use), unless you specify by a directive or switch that you want to allow non-ASCII bytes.)