I think interest is the first one.As we know interest is the best teacher;the second you should master a lot of words and some rules about grammer;the third one you should keep on.There are only two creatures can surmount the pyramid: the eagle and the snail. So we should practice our perseverance,we never give up because it is hard or inconveniet.
if you want to learn English well, maybe you can find a partner.You can recite something together and practice English in pairs.You should help each other and learn from each other.