These are the things that will make a difference and, unsurprisingly, they are hard work. Practice doing them now and you will do them better in the exam

• be systematic, starting with cadences then modulations, then fingerprints, then simple primary chord bass line and then refining before putting in inner parts (in other words, follow the method on ChoraleGUIDE)
• make sure your bass line has plenty of passing notes and is, as far as possible, a nice shape and that there are NO PARALLELS WITH THE SOPRANO
• use Fingerprints as often as possible
• add Bells and Whistles where you can, but don’t go too bonkers
• check it all very thoroughly, including the bass against the soprano again for parallels and be prepared to make radical changes if necessary
• check for ACCIDENTALS and where you put them in late, check they don’t create augmented intervals or mess up pivot chords
• play through each line separately to check for problems and if possible play them in pairs too, particularly the soprano and the bass