Layer 2
This layer builds over Layer 1 (pitch), and adds the duration of the notes. It does not consider the embellishments, except for those that are included in Layer 1.
The technique for this layer starts by identifying the longest notes in a music phrase. While sight-reading a tune, these notes are of great use to read ahead, as they give you time to read the following notes in the tune.
The contrary is that the comparatively short notes between one long note and the next long notes do not allow enough time to read and plan how you are going to get to the next long note. In other words, if you stop to think on a short note, you've likely played it for too long.
The simplified "long vs. short note" approach can later be refined in subsequent passes of the music phrase, considering the full breakdown of the relative duration of notes, dots-cuts and ties.
Example (Scotland the Brave, 1st part):