I recently decided to go to a golf pro to work on my irons and got a couple good things out of it:

He got me to take the club back less inside so that when the club was parallel to the ground (about halfswing) the end of the club would face the target and the toe of the clubhead would point to the sky. From this point all I had to do was raise the club up and it'll always on the correct plane on my backswing.

Also he stood directly behind me and told me to reach back with my right hand (for right handers) to pretend to shake hands with him (imagine doing this in the backswing). This helped in creating a wide arc for more power and accuracy.

I was also not transferring my weight correctly as I shifted forward a bit too early on my downswing (I should keep weight to back-center until I make contact with the ball).

I'm not sure if these tips will help anyone else out, but it made my irons further and alot more accurate.