Apple "option" keyboard shortcuts and touch typing Apple keyboards can have shortcuts using alt/option to type non-standard characters. For example, I can type the Swedish å by using alt+k and then typing a, and the Portuguese ç by using alt+c and then typing c. Now, from a touch typing perspective, how should I use these shortcuts? I mean, with which finger should I type them? I reckon that these resemble all the shift+key combinations, which I strike with the pinky of each hand, but the apple keyboard has only one alt key on the left side.
I had a similar issue but solved it in a different way.

I simply "modified" the keyboard layout to the level it suits my needs and uses.

If you press and hold a certain key example "a" a pop up will show me all options for it.



Here is how it works.

Find a file in /System/Library/Input Methods/PressAndHold.app/Contents/Resources   that is your keyboard Keyboard-??.plist (in my case it is called Keyboard-de.plist (German keyboard)

Copy that file to your Desktop (to modify it) since you can not modify the original file.

Open it (it will open in Text mode)

Find for example the "c" it looks like this (and I added the Portuguese ç)

&lt;key&gt;Roman-Accent-C&lt;/key&gt;
    &lt;dict&gt;
        &lt;key&gt;Direction&lt;/key&gt;
        &lt;string&gt;left&lt;/string&gt;
        &lt;key&gt;Keycaps&lt;/key&gt;
        &lt;string&gt;C Č č Ç&lt;/string&gt;
        &lt;key&gt;Strings&lt;/key&gt;
        &lt;string&gt;C Č č ç&lt;/string&gt;
    &lt;/dict&gt;


now add any "c" accents you like to use (Open the Character Viewer and find it) and just drag it over to the text file. 

Once done replace the original keyboard-??.plist file with yours.

Now you have a highly customized keyboard specific to your uses, and no need to remember some finger breaking key combination to get it.