MY STUDY PROCESS

To study English rules at first I read them for three or four times; than I start to repeat them until I know them perfectly.
Last but not least I try to think of some examples.
When I must do an English exercise, depending on what kind of activity it is, I apply the method that my English teacher taught me.

MY PROBLEMS

I often get bad marks because I’m very slow; so I never finish class tests in about an hour (time estimated to do an English class test).
Sometimes, I don’t understand the differences between some rules.
For example, to translate a past action older than another past action you use the past perfect , but to translate a series of past actions you use the Simple Past.
But if it is a series of past actions in the past there are some actions which are older than others, always do we use the simple past then.
What is the difference? Is it because in the Past Simple you consider a series of actions in the past while in the case of the Past Perfect only two action one older than the other?
understand there are many rules that you can apply, and I don’t know which is the right one I must use.