I usually write whatever I would say, then go over it after and take out any words or phrases that might be superfluous, or that can possibly be removed. Wholesale removal of extraneous stuff goes a long way towards making yourself clearer. I'll occasionally leave things in that I feel add to my "voice", but more often than not, if a word can be removed, it is removed.

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I write whatever I would say, then go over it and take out anything superfluous. It makes things clearer.