Use dynamics emotionally. Let the ensemble know where the music is going. Good musical shaping, spacing, strucural sense. Stylistic authenticity - must be true to the composer and his times. Must hear the middle parts.
Style is very important.
It is captivating. Suitable tempi - choice of speeds which allow the music to sound well. The whole duty, ability of a conductor is to deliver the tempi. Do notm present music as a metranome. Choose the speed at which the music sounds best.