This may seem like a minor thing in the world of writing -- and it probably is -- but the question arose: "How many spaces do I put between sentences?"
Ah, yes, the space question.
This only applies in, say, a paragraph where one sentence ends and the next begins. Like this one. Notice I used a double-space. That's my preference. It was how I was taught, and so it's what I do.
I know writers better than I who only single-space. Are they wrong? Or am I?
Technically, neither, but in formatting a raw manuscript, two is better than one. It helps with reading and comprehension and, at least to my eyes, just looks better.
But single-spacing won't get you rejected or keep you out of heaven. Generally, it doesn't matter, so if you're use to one, stick with it.
(But two is better.)