What all do I need to make quality homemade wine?

I have made my own wine before using bread yeast, water and sugar and either frozen g concentrate or kool-aid for flavor. My friend and his dad used to make it legitimately with vintner's yeast, water, sugar, yeast nutrients, legit wine flavoring stuff, and a few other ingredients. Needless to say his wine was of far greater quality than my milk jug wine. I don't really talk to him much any more so I can't ask what all ingredients he used. So what are the essentials to make good quality wine without making it too complicated?