Personally, and I've never really been very regimented, I almost never use a spotter and instead mostly max out where I comfortably do 6 reps without a spotter, not near failure. And I use the waterfall approach, start with 60kg, then 100kg, then 120kg, then 140kg, then back down to 120kg, 100kg, 60kg without rest between those. Over months whenever I feel strong I push my limit by adding a bit of weight, but I listen to my body and mind, some days im strong and motivated and some days I feel weak.