There are a variety of special tools for forcing deck boards in line. I use a couple of tools I always have with me – a Wonder Bar and a pipe clamp. Once I am too far from the edge of the deck to use only the pipe clamp, I push the Wonder Bar in the gap between already attached deck boards and use the Wonder Bar to anchor one end of the pipe clamp while the other end draws the board straight.
Thanks for considering my tip.
Charles Finkel