I hadn't given it much thought until your post, but on my 2017 13" MBP, here's how I seem to do it: 1. Put my right hand in approximately the correct location.

I hadn't given it much thought until your post, but on my 2017 13" MBP, here's how I seem to do it: 1. Put my right hand in approximately the correct location. 2. With my middle finger, find the space between the up/down keys. 3. Now my right hand's index finger is above the "left" key, and my right hand's ring finger is above the "right" key.