Here is a tip from www.golfdigestchallange.com by Chuck Cook:

"Stretch two strings from shafts stuck in the ground, as shown. From 10 yards back, hit wedges through the 'window.' Move back a yard and try it with a 9-iron, then continue moving back a yard as you work your way down through your iron set."

I have not tried it. I have been using an umbrella. I might use a wall as a target, too? Just to see how high I hit it. I am using birdie balls at my backward. The feel is not the same as in real balls, but I do not have room enough to hit them at home - and I do not dare to build my own practicing set up at the club.