For a serious shampoo, poo or no, I section in fours. If I'm just rinsing through to re-wet for styling, I sometimes work with just two sections - hair divided down the middle. Because I have 65-70% shrinkage in some areas and my hair is fairly long, sectioning is essential for me to clean the scalp without having a gang of tangles.
I used to do hot oil treatments before shampooing as part of my routine. I have'nt done any pre-shampoo anythings in a good while but I've been thinking of trying one by J.F. Lazartigue.