hi , mpierich is right about how hard it is to show how to polish over the internet
we can only try to guide you , and you will have to learn to use what works best for you , also with practice you will know when you have to buff longer or when you need to put more pressure , an you will also learn that on some parts even if you keep putting more hours on them they don t get any better
as for the emery mpierich is right but you were not wrong .
he mostly sands 320 or 400 then the emery ,
i usually go to 600 then a tripoli, but we both get same result
do what works best for you.
from the pic i see it looks like the polishing lines are going up and down on the part , i try to have the lines follow the length of the part , lines will still be there .but instead of seeing 450 small vertical polishing lines you will see 50 long polishing lines (easier on the eyes )
and always keep your buffing wheels very clean( rake them often)