This was in a post by Denny_D to amberwish that I found helpful.
"What I would suggest is that just cut the film in half, and then in half again, and then in half once more. You will end up with (8) - 1mg pieces right? Cut those in half again and you will have (16) - 0.50mg pieces. One more cut in half and you will end up this time with (32) - 0.25mg pieces........."
".......just take the 0.25mg piece and cut that in half and you get 2 pieces of 0.125mg " so that will be (64) .125mg peices. Good luck
I used to use tweezers myself. I did the same thing slicing them in half as precisely as I could. I actually found it easier to use a razorblade because when I used scissors I would cut them unevenly because of the thickness of the scissor blades making it seem like I was centered but they ended up pretty uneven.
I used to cut them in half repeatedly though, definitely the most accurate way. I also found using a pill holder each week helped me keep track of things much easie.