I do the same as others, divide into light and dark and place in a 2 gallon plastic bag. I pull from the bag about 30 at a time and eliminate duplicates by throwing the duplicates in an open plastic tote. Just the 30, not the entire bag. So when I sew, I know at least my block doesn't have duplicates. Once I go thru the entire bag, I rebag them and start over. Whatever size block I am making. When I sew the blocks together, I don't worry about the closeness of like squares because they are divided into a checkerboard pattern. So two of the same whatevers are corner to corner not side to side.