Feel that your trail side chest, shoulder, hips are going through impact along with your trail hand and club.
Most folks who flip.. varying degrees.. have a tendency to hang back and throw club at the ball.
Keep at it. It can take a long time to get there. The feel for it is going to be different for everyone. What is your instructor having you work on? If they are good it will be fixing basic things first or how you are moving in the swing first to get you to not flip down the line. It probably won't be a quick fix, but as you work on the various movements in the swing you will get there.
I flip my wrist at the ball and I am taking lesson to overcome it. After 3 weeks it is still a problem. There are hundreds of videos on youtube suggesting various drills such as work on weight shift by stepping your left foot forward, bow your left wrist at top of backswing, hitting stinger shots only at the range, practice swing without the balls. Can you share your experience on overcoming your flipping problem? What was the most effective drill and how long did it take to have lag in your swing?
I've played the forward tees at my home course a few times. It's a good change of pace and good practice. It can also be a good confidence booster, to know that you can mentally can break through those barriers you set for yourself. I would like to do it more often, but I don't get to golf enough to make me feel like I can do much practice like that on the course.