This entire paragraph and list that follows, but it was number six in the list that I thought I could use best.
“MOTIVATE your reader to WANT to know the past. That means: make the past important to him. Which is to say, make the facts to be presented important to your story, and to the PEOPLE in your story. THEN set the facts forth in a manner that allows your characters to appear normal… Techniques which may help you achieve this worthy end include:
1) cut to the bone the amount of information you give your reader
2) break up the essential content —instead of shoving a half page of past history at me in a lump, like soggy, dripping laundry, maybe you could plant the husband’s name in one spot, his death in another, her penury in a third, and so on…
3) make someone NEED the information… you motivate your reader when you set someone in search of NEEDED information.
4) make that someone have to fight to learn what he needs to know.
5) tie information to action.
6) motivate some character to pay attention to anything you want your reader to notice.