I lay the blocks out on the floor or on the design wall if it's big enough. I print out a table that starts with 1A, 1B, 1C... 2A, 2B, 2C,... and progresses through all the numbers and letters needed for the quilt. I cut the labels out and pin them to the upper left corner of each block, so on the floor I see 1A, 1B, 1C,...across the first row, 2A, 2B, 2C,... across the second row, etc. Then I stack each row up with the A column on top and start sewing. As I add a block, I take the label off that block, but I leave it on the first block in the row. When I'm done with the rows, I have a label on the first block of each row, and it's time to start sewing the rows together. If the quilt is huge I might sew it in quarters (row by row in each quarter, then all the rows together for that quarter) but the method still works.