I am confused; don't both of these words mean "more"? What is the literal meaning and context of each? Sample sentences would be helpful! спасибо!
I'd say ещё implies a continuing process, like putting food on a dish or enumerating objects, in positive sentences, while больше is used in negative sentences and when discussing sizes.
Ещё мне добавь - Give me more (money, food)
Больше не надо - Don't need more (goes with anything)
А ещё больше есть? - Do you have an even bigger one (shirt, car)?