Which word do you prefer with the use for English “more”: “больше” or “более”?
Only более is used to form the superlative of adjectives and adverbs. Он более грамотный, чем его сестра.
In the meaning of “in bigger amount” or “to a bigger extent” we use both, более being more bookish. (What is the synonym to bookish?) I hardly ever use более in this meaning. Добавь больше муки в тесто.