Jim Furyk was ridiculed for his golf swing the moment he came out on tour. Funky looking swings can function better than truer looking swings because of opposite force and pressure. Here is what Furk's funky swing does better than anyone else has done over his career.
Swinging Left- It's something we have all heard about but very few can put their finger on the true source of just how it happens. Watch and learn HOW to get the hands to work left whilst the clubhead stays square and down the target line.
The plane of the left arm- whilst having a few options is best served to line up in a particular manner at the top of the backswing. This helps keep a synchronization of the shoulder turn and arm travel.
Many over the top swings are from a lack of flexibility- especially in the right shoulder. Here is a quick tip to help you gain mobility in the right shoulder to help you stop coming over the top on the downswing.
When working on swing drills it is important to understand that slow motion drills often need to be exaggerated. The reason? Because force and motion will significantly alter the appearance of what you are trying to establish in the swing.
Remaining in posture- keeping the tushy line intact and how to avoid early extending the body are questions that litter golf forums searching for the answer. Here it is in this recent video.