I love reading and editing my manuscript on my computer. I can edit as I go along without having to go back to it later. 
Problem is, even after reading and editing my manuscript a dozen times onscreen, I could still miss typos, bad breaks, and other mistakes.
Just like reading your manuscript out loud, there is something helpful about editing your work by reading a hard copy of your manuscript. Seeing what you wrote on paper helps you see mistakes that you might have missed onscreen.
To save on trees, I only do this exercise after I’ve edited quite a bit onscreen. 
If you haven’t tried reading your manuscript on paper, try it.
I do this every five chapters or so…print them out at Staples and go to town with the red pen. It definitely works.
It really makes a difference, doesn’t it? I need to do it again soon. Hoping not to use the red pen as much this time.
Printed the dang thing out again last week. Argh! Will it ever end?!?!
Lol. I know what you mean.