When in a word processor document, you can use the Preferences dialog (found via Tools > Preferences …) to save special keyboard shortcut codes for any common symbols you have to type. By default, Google already supplies you with some handy ones, but gives you the option to add as many more as you need:
For example, I live in Spain so I find myself often using the Spanish language; but since my computer has a British keyboard layout, accessing some of the accented characters can be a hassle.
Instead, I save character combinations that I’d rarely (if ever) need in their original form, and ask Drive to convert these into the language-specific characters I regularly need:
The entry in the image shows one example. Having saved this combination as a preference, every time I enter the code
into a document, Drive will convert this for me to
Of course, I can enter similar codes for other symbols I might require such as é, á, ¿ and so on.
You can use this ability for much more than multi-lingual text. If, for example, you find yourself writing the same phrases often, you can shorten each of them to a code:
These codes are not just available for your current document, once saved they are available for any document you create in Drive.