If you got top rankings because you were "lucky" then the right strategy is to make hay while the sun shines and put a little aside for the rainy day.
In Google SERPS there's only one #1, one #2 etc. Panda changed the rules on how you get to #1, #2, #3 but it did so by measuring stuff about web sites and pages. It is measuring different things and mixing up the factors in a new way but at the end of the day Google is still using data it has measured.
To have a successful Google fed website now is exactly the same as it was before. You need to find the things that Google measures and values and do those things. You might do that by luck or by judgement. If you do it by luck start reading at the top again. If you do it by judgement then when things change next time you will be in a good position to change with it.