Various things I've figured out that make my life a little easier ...
Since I'm human, I use the delete key on my computer a lot, and because it's right next to the insert key, I occasionally press it by accident. Unlike most missed keys, it doesn't normally insert a character into the document I'm typing; rather, it puts the editor into overstrike mode, so that whatever I type next replaces what I've typed before. This means that instead of erasing an unwanted character, I've left the unwanted character intact, removed some characters I wanted to keep, added characters I need to remove, and put the keyboard in a mode I don't want it to be in.
To reduce the cost of this "typo," I've changed the function of the insert key so that instead of switching modes, it inserts a character. To get my attention (and symbolize my dismay in having pressed the wrong key), I've chosen the frown character from the Wingdings font. To set this up, I selected "Symbol..." from the Insert menu:
and then set the Shortcut Key:
The result is that when I mistakenly press the insert key, I get this:
which both alerts me to my mistake and makes it much quicker to correct.