Both.
I squiggle by hand, then consolidate it into typed text.
Then I squiggle all over the typed text, adding and correcting.
Then I type up all the changes to form a neat, typed text again.
Then start squiggling again.
And so forth....
I find creative work is easier by hand. More spontaneous.
But typing it up is helpful in forming it into something useful.
Typing and retyping also prevents things sliding into a jumbled chaos of squiggles, additions and arrows which I soon after can no longer decipher.
Sua cuique voluptas, as old chickpea would say.