Rule #2: Dump the Ballast. In order to write authentic historical fiction you must know a period of time well enough to disappear daily through a wormhole to the past and arrive at the location of your story. There you must understand the customs and use the manners perfectly enough to be accepted by people walking the streets (if there are streets) and to dress yourself, and make a living. This said, the major trick of writing good historical fiction is not in compiling research or knowing the details, but in knowing the details to leave out. Try to avoid overwriting. Keep perspective on what will interest the reader. Historical fiction writers tend to be overly conscientious and excited by minutia: if you succumb to excess, and put in too much detail, then go back later and take some of it out.

Think of your novel as a boat that is about to sink from having too much weight on board: some of the loved items will have to go. Toss them over with impunity! Throw them out! If a rare, surprising statistic, or a moving anecdote, or an obscure reference you saw to an interesting thing that happened in the county adjacent to the one where your story takes place, does not advance your plot or provide your reader with important information about your characters, then it is irrelevant to your story and must go overboard.

Keep in mind that the care, and time, it took to assemble all that you have just thrown out has not been wasted. It was necessary to gather these facts and assess their worth in order to know which ones to save.

PS. I'm guessing that Elizabeth is speaking directy to me here, as I have a tendency to collect odd facts.  Yestrday on our travels, I met a cat with half a tail and learned she had survived Katrina.  Further down the road, we saw a woman police office who carried bright pink handcuffs.  How humiliating! Will I find a place for them in a future book?  Maybe not, but . . . .