One of my stories has four points of views (a father and his three sons). The sequel has five (a father, two sons, a daughter-in-law and a grandson)
I find it fairly easy to stay in the right head because they view each other differently to how they view themselves. Each one has a different voice and tone so it feels wrong when I hop into another head.
For example, I can write a scene from the point of view of the father in my story and he sees his eldest son as a big kid, a fifty-year-old man who has never really grown up. He describes him as lanky with four facial expressions, cheeky, funeral, happy and "I've done something you're not going to like, so please don't kill me".
Said fifty-year-old man is under the impression his boss has taken him on because he's handsome and eye-candy for her clients.
The same fifty-year-old man is viewed by his son with anger for a variety of reasons but you also see his love for his dad (which doesn't come across in fifty-year-old man's POV)
The father presents himself as an older man, and a bit of a scruff, but when a forensic pathologist describes him she mentions he has beautiful eyes, handsome face but a disappointing backside.