We like to do single leg deadlifts and one arm overhead carries. (coachdebbieruns.com)
Stiff - Leg Deadlifts, or single leg deadlift unweighted (targets lower back, erector spinae column, hamstrings) (thebettyrocker.com)
Even the basic swing has a great hamstring stretch and other exercises such as the windmill, and single leg deadlift also build massive flexible strength. (theathleticbuild.com)