Lesson 2 (These spokes are in my hand so not in exact position/angle they would be if in a rim.)
This is how I do it - because I don't do it often enough for it to be instinctive.
Start with 4 spokes - two each side, heads pointing complementary ways.
There are six holes between them if the wheel is to be built 'cross three'.
Fix to rim around hole (above photo) so that there is biggest gap for the valve.
Then add the rest of the spokes in the same pattern - alternating heads on the hub and from left and right at the rim.