I pin all the blocks together for the row and then sew them. I continue until I have all ten rows (in this case) sewn together.
Once that is done I stack the even numbered rows together 1,3,5,7, and 9 and then 2,4,6,8 and 10. I take the stacks of rows to the ironing board and then get ready to press.
I give them a squirt of spray starch and press all the odd numbered rows towards the pin and the even numbered rows away from the pin.
This way the blocks from each row will "butt" one another and sewing the two rows together will be easy and time saving.