Choose a straight piece of flooring for the last row. The cuts shown are what I typically make for the floor go in as you need. Drill pilot holes before you set the floor in place. Angle them slightly so the process of driving the nail keeps the joint tight. Be certain you size the holes right. The shanks should just fit through, and the head of the nail not. Get this right, use a drill bit to the 1/32" increment to get it right.
Set the piece in, using glue at the tongue if you choose too. Place the nails in the pre-drilled holes, and use the nails to pull the floor into place. Tap the piece to vibrate it if needed, it really helps moving tight pieces. Set your nails and countersink them.