Look, like most of these things, the answer is "what works for you". Personally, I have to keep pushing on -- if I look back, my Inner Critic starts asking for other changes, and as Satchel Paige said "never look back; something might be gaining on you."
On the other hand, I know people who practice the shitabrick method, and have to get each paragraph exactly right before they can go on.
So, how about this: try some freewriting -- write as fast as you can, ignoring errors and all, and see if you get into that nice warm-bath feeling of "flow". If so, forget the spelling, that's why God made spell correct.
If, after you give it some time, it doesn't work, then try fixing errors as you see them.
There's no one looking over your shoulder saying "you're not right the Correct Way", except possibly you.