I do mine same and similar to lots of others, when I lay out the blocks, I label each block with piece of masking tape. If it's row 1---- then I put 1-1,1-2,1-3, and so on. As in row 1 block 1, row 1 block 2
Then row 2 2-1, 2-2,and so on. I put tape in top left corner. But make sure to remove all but your row 1 1st block trape before ironing. The tape can leave a residue that won't come off, if you don't.
The tape on row one, block one on top left corner tells you where the top corner is all the way thru. Make sense?