The way I look at the zones: if they do not pop up nicely immediatelly, you can first search for big candles and then to search for the indecision zones that caused the move. It helps if while marking them you switch timeframes to get a nice area...
That's one of the best way to go about finding the right areas of volume for potential reversal or continuation of price with an impulsive move based on price momentum.
I am not sure if I agree with the book. You should enter trades when your conditions are fulfilled. Therefore, you should not risk more ("larger bet") if you feel the trade is extraordinary. Risk should stay the same. If the reward is higher (RR ratio), even better. But I would not increase the risk.