I shimmed the rear of my 95 accord on H&R Sport when I lowered the car. I put 2x2 washers on each side. It has noticeable negative camber but I was aware of that. I rode on it for 3 months and last Saturday I went to get an alignment. The reading for the rear were: -1.8 and -1.2 What caused the big difference? By looking at the treadwear, both side has about the same negative camber Machine error? The guy doing the alignment was pretty good.
BTW, Most ppl tell you toe isnt affected when you lower your car but it DOES and it will eat the shit out of your tires

 

so add another washer? i used two pretty big washers and came out with -1.0 and -0.9

 

whoever told you that doesn't know anything.. toe is your main concern when lowering a car.. that's why an alignment is needed.. camber isn't able to be changed on most cars without a camber kit.. so the only thing adjusted is toe..