(Not sure where this belongs as I'm new to FTR, hopefully this is the right subforum)

1. I play heads up sng at low/mid stakes. When playing a weak, non-handreading opponent (which is the case about 80% of the time), does it make any sense to think about both players' ranges? My understanding is that against this kind of player ("fish") it's sufficient to just play my hand vs his range, instead of my range vs his range. It seems obvious to me but maybe I'm underestimating the value of reading both ranges even vs fish.

2. How do you visualise ranges? Preflop it's not that difficult but I have trouble with the postflop part. What kind of training is recommended for improving range reading postflop?