I wouldn't finish with a bull unless you are a seriously good level. From there is personal preference. i always like finishing on trhe right side of the board rather than the left -- unless its a double 14/12, something high. So, treble 17, treble 16, double 12. If I miss the treble then I 9should) have 106 left, from there you still have options to try and leave your favourite finish. Miss the treble 16 then with 56 left there are still a wealth of options. 16, tops maybe.