Yes, knowing how to "hand size" full-floater bearings is a combination of art and science, it isn't that tough if you really think about what you're doing, can correctly measure clearances and keep the end goal in sight --> full floaters . . . must easily float on both bearing surfaces (the crank journal and the rod inside bore). Here is a short little video that might help you a bit.
https://www.youtube.com/watch?v=CyVLsPdbhS8&t=17s