Where do you start and end?

In the circle of life, you have an obligation to picture your ending from the beginning it's more like writing a story. You have to think of the plot, then the conflict and the resolution so you don't hang up somewhere without a knowledge of what to write about.

In the cycle of ignorance, is it to thank God for good things and to blame one's fate for bad things?

In everything, give thanks shifting blame on anyone or anything won't really change a situation.