I number my rows and blocks seprately and dont take them off untill im all done..
row 1 blk 1, row 1 blk 2
row 2 blk 1, row 2 blk 2 and so on.
I have taken toooooo many apart because I sewed them in the wrong spot, upside down, and this is not sure proof either because let be said ive sewn out of sequence b4 lol.