Proper Footing

Drop your trail foot back for easier rotation
Dropping your trail foot back (right foot for right-handed players), slightly behind your lead foot, is one of the simplest setup changes you can make.

I use it myself sometimes when hitting long irons because it just leads to better results.
 
When you drop your trail foot back just slightly, it leads to a naturally closed stance, which helps encourage more hip and shoulder turn, even if you’re somewhat stiff. The club has an easier time travelling more from the inside, and you should see a draw or at least less of a slice.
 
Bonus Tip:
Try flaring both feet out slightly at the address.
This frees up your hips even more, making it easier to turn back and through.