This is where something like Scribble would be useful if it could let you write and draw in your own handwriting, and then fix things up along the way to look highly professional. E.g. if you draw a square quickly and title it Square, you’d end up with straight lines and the word Square neatly drawn on top of it. Even better if could be stylized with different drawing flavors.
While Scribble can do a little or it by correcting shapes if you are careful enough as you draw, it isn’t able to “autocorrect” hand drawn titles by replacing with rendered text.