Human felicity is produced not so much by great pieces of good fortune that seldom happen,as by little advantages that occur every day.---Benjamin Franklin.
与其说人类的幸福来自偶尔发生的鸿运，不如说来自每天都有的小实惠。

basically break up the sentence and those are the things you want to discuss.

how luck is a bad way to achieve happiness
-luck is unpredictable, therefore one cannot depend on luck
-luck cause laziness, as in one would wait for luck instead of trying
-if one only achieves by luck, then in its absense achievements becomes impossible.

how "little advantages that occur every day" is a good way to achieve happiness
-predictable, something to depend on
-how slight advantages over a long time can add up
-constantly trying for that little advantage, getting a habit of trying hard
-developing regular habits, thus a regular lifestyle

etc
etc