Your briefs probably suck. I mean, I think they’re fine, but Chris Mincher has some advice for you:
The use of monospaced characters on typewriters led to another obsolete yet stubbornly persistent practice — putting two spaces between sentences. With uniformly spaced type, a period has the same space between the last letter of the sentence it’s finishing and the first letter of the next sentence. In this case, an extra space helps create an easier visual cue signaling the start of a new sentence. However, these days, word processors and proportionally spaced fonts place the period flush with the previous letter, thereby leaving plenty of room to serve that function.
Putting an extra space on top of that is absolute overkill, and if those gaps happen to coincidentally align vertically, it can lead to a disrupting ribbon of white running down your document. Two spaces are therefore not only totally unnecessary, but also a potential obstruction to readability, and you should never, ever use them. Anyway, just wanted to get that off my chest.
Amen, brother! Actually, the bulk of his post is about typography – your choice of font, spacing, margins, and so on. Like me, Mincher has read Butterick’s Typography for Lawyers, and is more competent a designer as a result. If you’re lawyering and you’re using Times New Roman, you owe it to yourself to read this. Mincher is a good place to start.