I use Post-It notes ... I lay them out labeled and put the screws on top of the note. I have never had a problem losing them or having one left over using this method.
With the Poster Putty, the screws stick to the paper very securely and it/they can be moved around without risk of the screws falling off. I just put them on top of the parts and set them aside.
I use cardboard - make an indentation (hole) with a screw driver in the cardboard - put the screw in the indentation - obvious the indentation matches the layout of the laptop
this works great and can neatly store each layer of cardboard on top of each other if you have to wait for parts