* Refrain from writing of past events in the present tense. One should, not for example, write, George Washington appoints Alexander Hamilton the Secretary of the Treasury. The reason one should not do that should be obvious. Just in case it is not, I will explain it: Washington appointed Hamilton to that post in 1789, in the past.
* The active voice is superior to the passive voice. Avoiding the passive voice can become awkward in a few cases, such as She was born (although I have found elegant ways of avoiding the passive voice in even that circumstance), but the passive voice is almost always awkward. Write with a preference for the active voice. Use the active voice as much as humanly possible. I AM MORE CATHOLIC THAN THE POPE, SO TO SPEAK, REGARDING THIS MATTER.