How to paint an oil portrait

I use flax based canvas. The final size is 40 x 50 cm. For each step, I take about 30 to 60 minutes, so I do a portrait in about 5 to 8 hours average. Step 1 First I draw in pencil on the canvas. .Step 2 Then I add the first highlights flesh color. .Step 3 Then entour these highlights with darker flesh color. .Step 4 And again, darker.