It's really a matter of personal preference as you can see. Some people like to line up the bar pull with the shaker trim, some like to drop it a little from there. Some even like to put them in the middle of the door (I personally don't like that, but....) For a more contemporary look, some like to install them horizontally instead.

loving the horizontal

My cabinets are shaker as seen in these example images.

I have two questions:

1) use the same size pull throughout?
2) mix up sizes according to shaker panel?

In personally like one size throughout, but want other opinions. I’ve attached image showing smallest size cabinet.

I am also about to get Shaker style cabinets. I'm going with 9in pulls on all the cabinets except for the one below the cooktop. The cooktop cabinet will be 39in so it will need either double pulls or larger pulls. I prefer, for both practicality and aesthetics, to have larger pulls rather than double on such large cabinets.