So you’ve judged the lie, picked the correct club, and adjusted your setup. Now it’s time to hit the shot. The thing to remember when chipping from thick rough is that the swing needs to be steep. It has has to come in at an angle so that it hits the least amount of grass possible before hitting the ball. If you “pick” or “scoop” your shots around the green, playing from long grass will be next to impossible without making adjustments.
As you start the backswing feel your wrists hinging upwards so the golf club works up and away from you. If your club goes inside or behind you on the backswing, you’re going to catch too much grass on the downswing. Take a few practice swings and get the feel for the wrist hinge and the club working up. Once you’ve got a feel for the backswing you can start to work on the bottom of the swing. At impact you want to feel the clubhead get down in the grass. It’s like a chopping motion with the clubhead working up and then abruptly down. You should feel the bottom of the golf club contacting the ground. If you try to “scoop” this shot you won’t have much success.
Lastly there is not much follow through with this shot. Between the golf club hitting the thick grass and the golf club contacting the ground, a lot of the club’s momentum will be lost. You should not try to slow the swing down to shorten the follow through. Just let it happen naturally. The motion of leading with the hands, the grass, and the ground will do this for you. To summarize, when chipping from thick rough you need to: judge the lie, use a club with more loft, setup for a steeper swing, and play the shot with a steep motion down into the grass. If you do this you will have more success and get more shots up and down.